Suture securing tool

ABSTRACT

The present invention relates to a suture securing tool for securing a suture against body tissue with a suture retainer. The tool includes first, second, and third force application assemblies. The first force application assembly is connectable with at least one end portion of the suture for tensioning the suture with a suture tensioning force which is a function of suture size and strength. The second force application assembly presses the suture retainer against the body tissue and has an opening through which at least one end portion of the suture is extendable. The third force application assembly plastically deforms the suture retainer to thereby secure the suture against body tissue.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/685,795, filed Oct. 10, 2000 now U.S. Pat. No. 6,569,187. Theaforementioned application Ser. No. 09/685,795 is itself a continuationof U.S. patent application Ser. No. 09/348,940, filed Jul. 7, 1999 (nowU.S. Pat. No. 6,159,234). The aforementioned application Ser. No.09/348,940 is itself a continuation-in-part of U.S. patent applicationSer. No. 08/905,084, filed Aug. 1, 1997 (now U.S. Pat. No. 6,010,525).The benefit of the earlier filing dates of the aforementionedapplications is hereby claimed.

BACKGROUND OF THE INVENTION

The present invention relates to a new and improved method and apparatusfor securing a suture against movement relative to body tissue by usinga retainer to grip the suture.

Difficulty has been encountered in securing sutures against movementrelative to body tissue. A knot may be tied in a suture to preventloosening of the suture. However, the knot weakens a portion of thesuture and reduces the overall force transmitting capability of thesuture. In addition, a suture which is held by a knot applies force to arelatively small area of the body tissue and tends to cut or separatethe body tissue. Many operations are conducted in very restricted spacewhere the tying of a knot is difficult.

Various methods of securing a suture against movement relative to bodytissue are disclosed in U.S. Pat. Nos. 3,513,848; 4,662,068; 4,935,028;5,306,280; and 5,593,425. Although these and other known methods ofsecuring a suture have, to a greater or lesser extent, been successful,it is desirable to simplify the securing of a suture against movementrelative to body tissue. It is also desirable to be certain that thesuture applies a desired amount of force to the body tissue when thesuture is secured. The overall force transmitting capability of thesuture should be maximized without concentrating the force at a smallarea on the body tissue.

SUMMARY OF THE INVENTION

The present invention provides a new and improved method and apparatusfor use in securing a suture relative to body tissue. A suture retainermay be plastically deformed to grip the suture. The plastic deformationof the suture retainer may include pressing the material of the sutureretainer against the suture by cold flowing material of the sutureretainer. The plastic deformation of the material of the suture retainermay be performed while transmitting a predetermined force from thesuture retainer to the body tissue.

The strength of a connection between the suture retainer and the suturemay be increased by forming bends in the suture before deforming thematerial of the suture retainer. As the suture retainer is moved alongthe suture toward the body tissue, the bends are moved along the suturewith the suture retainer. The bends may be formed by wrapping the suturearound a circular portion of the suture retainer, by moving the suturethrough one or more passages in the suture retainer, by bending thesuture around a member, and/or by deflecting a portion of the sutureretainer through which the suture extends.

The suture retainer may be gripped with a tool which is moved along thesuture to move the suture retainer toward the body tissue. The tool maybe used to urge the suture retainer toward the body tissue with apredetermined minimum force. In addition, the tool may be used toplastically deform the material of the suture retainer when the sutureretainer has been moved to a desired position.

A suture having a known strength may be selected from a range of sizesof sutures. The selected suture is tensioned with a force which is afunction of the strength of the suture. While the suture is tensionedwith the force which is a function of the strength of the suture, thesuture is gripped by a retainer to maintain the tension in the suture.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the invention will become moreapparent upon a consideration of the following description taken inconnection with the accompanying drawings wherein:

FIG. 1 is a schematic illustration depicting the relationship of asuture retainer to a suture and body tissue prior to tightening of thesuture;

FIG. 2 is an enlarged sectional view illustrating the manner in whichthe suture is wrapped around the suture retainer of FIG. 1 to form bendsin the suture;

FIG. 3 is a schematic illustration depicting the manner in which thesuture retainer of FIG. 2 is pressed against body tissue with apredetermined force and the manner in which a predetermined force isapplied to an outer side surface of the suture retainer to plasticallydeform the suture retainer;

FIG. 4 is an enlarged fragmentary schematic illustration of a portion ofFIG. 3 and depicting the manner in which the material of the sutureretainer grips the suture;

FIG. 5 is an enlarged fragmentary view of a portion of FIG. 4 furtherillustrating the manner in which the material of the suture retainergrips the suture;

FIG. 6 is a schematic pictorial illustration depicting the manner inwhich a suture is positioned relative to a base of a second embodimentof the suture retainer;

FIG. 7 is a schematic illustration, taken along the line 7—7 of FIG. 6,depicting the manner in which a movable arm presses a portion of thesuture into a groove formed in the base of the suture retainer to formbends in the suture;

FIG. 8 is a schematic illustration depicting the manner in which forceis applied against the suture retainer of FIGS. 6 and 7 to plasticallydeform the suture retainer;

FIG. 9 is a schematic illustration depicting the manner in which asuture is wrapped around another embodiment of the suture retainer toform bends in the suture;

FIG. 10 is an enlarged fragmentary sectional view, taken generally alongthe line 10—10 of FIG. 9, illustrating the manner in which the suture isdisposed in a groove in the suture retainer;

FIG. 11 is a fragmentary sectional view, generally similar to FIG. 10,illustrating an alternative configuration for the groove in the sutureretainer of FIG. 9;

FIG. 12 is a schematic illustration depicting the manner in which forceis applied against the suture retainer of FIG. 9 to plastically deformthe suture retainer and grip the suture;

FIG. 13 is a schematic illustration depicting another embodiment of thesuture retainer and the manner in which sections of a suture are wrappedin opposite directions to form bends in the suture;

FIG. 14 is a sectional view, taken generally along the line 14—14 ofFIG. 13, illustrating the manner in which the suture is disposed in agroove in the suture retainer;

FIG. 15 is an enlarged fragmentary schematic illustration of a portionof FIG. 13, further illustrating the manner in which the suture isdisposed in grooves formed in the suture retainer;

FIG. 16 is a fragmentary schematic sectional illustration of the mannerin which the grooves and sections of the suture of FIG. 15 cross;

FIG. 17 is a schematic sectional view illustrating the manner in which asuture is wrapped around a roller in another embodiment of the sutureretainer;

FIG. 18 is a schematic illustration depicting the manner in which thesuture retainer of FIG. 17 is urged toward body tissue and the manner inwhich force is applied against the suture retainer to plastically deformthe suture retainer;

FIG. 19 is a fragmentary schematic illustration, generally similar toFIG. 17, depicting an alternative manner of wrapping the suture aroundthe roller;

FIG. 20 is a fragmentary schematic illustration of another embodiment ofthe suture retainer in which a housing encloses a plurality of cylindersaround which the suture is wrapped;

FIG. 21 is a schematic illustration depicting the manner in which thesuture zigzags through passages in another embodiment of the sutureretainer;

FIG. 22 is a schematic sectional view, taken generally along the line22—22 of FIG. 21, further illustrating the manner in which the sutureextends through the suture retainer;

FIG. 23 is a schematic sectional view depicting the manner in which thesuture zigzags through passages in another embodiment of the sutureretainer;

FIG. 24 is a schematic sectional view illustrating the manner in whichturns of a suture are wrapped in looped around another embodiment of thesuture retainer;

FIG. 25 is a schematic sectional view illustrating the manner in whichturns of a suture are wrapped in looped around another embodiment of thesuture retainer;

FIG. 26 is a schematic sectional view illustrating the manner in which atwo-section embodiment of the suture retainer is positioned relative tobody tissue prior to engagement of the two sections of the sutureretainer;

FIG. 27 is a pictorial illustration of an inner or lower section of thesuture retainer of FIG. 26;

FIG. 28 is a pictorial illustration of an outer or upper section of thesuture retainer of FIG. 26;

FIG. 29 is a schematic sectional view of another two-section embodimentof the suture retainer prior to engagement of the two sections of thesuture retainer;

FIG. 30 is a schematic illustration of another two-section embodiment ofthe suture retainer;

FIG. 31 is a pictorial illustration of an inner member used in thesuture retainer of FIG. 30;

FIG. 32 is a schematic sectional illustration depicting the manner inwhich another embodiment of the suture retainer is pressed against alarge area on body tissue with a predetermined force;

FIG. 33 is a schematic view of the suture retainer of FIG. 32 after thesuture retainer has been plastically deformed to grip the suture;

FIG. 34 is a schematic illustration depicting the manner in whichanother embodiment of the suture retainer is pressed against body tissueand the manner in which force is applied against the suture retainer toeffect plastic deformation of the suture retainer;

FIG. 35 is a schematic illustration of a tool which may be used to pressthe suture retainer of FIG. 13 against body tissue and to plasticallydeform the material of the suture retainer;

FIG. 36 is a schematic illustration of another embodiment of a toolwhich may be used to press a suture retainer against body tissue and toplastically deform the material of the suture retainer;

FIG. 37 is an illustration of a chart of available suture sizes andknown strengths for each suture size;

FIG. 38 is a schematic illustration depicting the manner in which asuture is tensioned, a suture retainer is pressed against body tissue,and force is applied against the suture retainer to plastically deformthe suture retainer; and

FIG. 39 is a schematic illustration, generally similar to FIG. 38,illustrating another embodiment of the invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

Embodiment of FIGS. 1-5

A suture retainer 50 (FIG. 1) is utilized to secure a known suture 52against movement relative to body tissue 54. The suture 52 extendsthrough an outer layer 56 and an inner layer 58 of the body tissue. Thesuture 52 has been illustrated schematically in FIG. 1 as extendingthrough passages 60 and 62 in the outer and inner layers 56 and 58 ofbody tissue 54. However, the suture 52 could be sewn through the bodytissue without forming the passages 60 and 62 in the body tissue.

Although the suture 52 has been shown in FIG. 1 in association with softbody tissue, it is contemplated that the suture 52 could be associatedwith hard body tissue. It is also contemplated that the suture 52 couldextend through a suture anchor in a manner similar to that disclosed inU.S. Pat. Nos. 5,584,862; 5,549,631; and/or 5,527,343.

The suture 52 has a left section 66 and a right section 68. The left andright sections 66 and 68 of the suture 62 extend through the sutureretainer 50 (FIG. 2). If desired, the suture 52 could be integrallyformed as one piece with the suture retainer 50. If this was done, anend of one of the sections 66 or 68 of the suture 52 would be connectedwith the suture retainer 50.

Although the sections 66 and 68 of the suture 52 could extend straightthrough the suture retainer 50, it is preferred to form a plurality ofbends in the suture 52. In the illustrated embodiment of the invention,two bends 72 and 74 (FIG. 2) are formed in the left section 66 of thesuture 52. Similarly, two bends 76 and 78 are formed in the rightsection 66 of the suture 52. If desired, a greater or lesser number ofbends could be formed in each of the sections 66 and 68 of the suture52.

The bends 72 and 74 (FIG. 2) are formed in the left section 66 of thesuture 52 by wrapping a turn 82 in the left section of the suture arounda portion of the suture retainer 50. Similarly, the bends 76 and 78 areformed in the right section 68 of the suture 52 by wrapping a turn 84 inthe right section of the suture around a portion of the suture retainer50. A single loop 86 is formed in the left section 66 of the suture 52around a portion of the suture retainer. Similarly, a single loop 88 isformed in the right section 68 of the suture 52 around a portion of thesuture retainer 50. A greater or lesser number of loops could beprovided in the left and right sections 66 and 68 of the suture 52 ifdesired.

The suture retainer 50 has a spherical configuration. A cylindricalpassage 92 extends through the center of the spherical suture retainer50. If desired, the suture retainer 50 could have a differentconfiguration. For example, the suture retainer 50 could have an oval orelliptical configuration. Although the passage 92 has a linear centralaxis, the passage could have a nonlinear central axis. If desired, aplurality of passages, having the same or different configurations,could be provided in the suture retainer 50.

The left and right sections 66 and 68 of the suture 52 extend throughthe passage 92. In addition, the left and right sections 66 and 68 ofthe suture 52 extend around a spherical outer side surface 94 of thesuture retainer 50. Thus, the loop 86 in the left section 66 of thesuture 52 extends around a left (as viewed in FIG. 2) hemisphericalportion of the suture retainer 50. Similarly, the loop 88 extends arounda right hemispherical portion of the suture retainer 50.

In the illustrated embodiment of the suture retainer 50, the left andright sections 66 and 68 of the suture 52 engage the smooth sphericalouter side surface 94 of the suture retainer 50. However, it iscontemplated that grooves could be provided in the outside of the sutureretainer 50 to receive the turns 82 and 84 of the left and rightsections 66 and 68 of the suture 52. Alternatively, projections couldextend from the spherical outer side surface 94 of the suture retainer50 to engage the suture 52.

After the suture 52 has been inserted through the suture retainer 50, inthe manner illustrated schematically in FIG. 2, the suture retainer 50is moved along the left and right sections 66 and 68 of the suturetoward the body tissue 54 (FIG. 1). To move the suture retainer 50 alongthe left and right sections 66 and 68 of the suture 52, the left andright sections 66 and 68 of the suture are pulled upward (as viewed inFIGS. 1 and 2) to tension the sections of the suture. A downward (asviewed in FIG. 1) force is then applied against the suture retainer 50.This downward force causes the suture retainer 50 to slide in a downwarddirection along the suture 52 toward an upper side surface 98 of thebody tissue 54 (FIG. 1).

As the suture retainer 50 slides downward along the left and rightsections 66 and 68 of the suture 52, force is applied against the leftsection 66 of the suture 52 at the bend 74. This force causes loop 86 inthe left section 66 of the suture 52 to move downward (as viewed in FIG.2) along the left section of the suture. At the same time, force isapplied against the right section 68 of the suture 52 at the bend 78.This force causes the loop 88 in the right section 68 of the suture 52to move downward along the right section of the suture.

The suture retainer 50 is formed as one piece of a polymeric materialhaving a relatively low coefficient of friction. Therefore, the twosections 66 and 68 of the suture 52 can readily slide along the outerside surface 94 and through the passage 92 in the suture retainer 50 asthe suture retainer is moved downward toward the upper side surface 98(FIG. 1) of the body tissue 54.

While a predetermined tension is maintained in the left and rightsections 66 and 68 of the suture 52, the suture retainer 50 is pressedagainst the upper side surface 98 of the body tissue 54 (FIG. 3). Thisresults in a connector section 102 (FIG. 1) of the suture 52 beingpulled tightly against the inner layer 58 of body tissue. In order toobtain a desired tension in the left and right sections 66 and 68 andconnector section 102 of the suture 52, the suture retainer 50 ispressed against the upper side surface 98 of the body tissue with apredetermined force, indicated schematically by an arrow 104 in the FIG.3. The suture retainer 50 increases the surface area on the body tissue54 against which force is applied.

Thus, while pulling on upper end portions of the left and right sections66 and 68 of the suture 52 with a predetermined force, the sutureretainer 50 is slid downward (as viewed in FIG. 1) along the left andright sections of the suture. The suture retainer 50 is pressed againstthe body tissue 54 with a predetermined force 104 (FIG. 3) which issufficient to obtain a desired tension in the left and right sections 66and 68 and connector section 102 of the suture 52. In this manner, adesired force, which has been preselected, is applied against the bodytissue 54 by the suture 52 and suture retainer 50.

Although the suture retainer 50 applies force against a far greatersurface area on the body tissue 54 than would be engaged by a know inthe suture 52, a force distribution member or button may be placedbetween the suture retainer and the upper surface 98 of the body tissue.A second force distribution member or button may be placed between theconnector section 102 of the suture and a lower side surface 108(FIG. 1) of the body tissue 54. If this is done, the main area ofengagement of the suture 52 with the body tissue 54 would be at thepassages 60 and 62.

In accordance with a feature of the present invention, once the sutureretainer 50 has been moved along the suture 52 and is being pressedagainst the body tissue 54 with a predetermined force 104 (FIG. 3), thesuture retainer is plastically deformed to grip the left and rightsections 66 and 68 of the suture. While the suture retainer 50 is beingpressed against the body tissue 54 with the predetermined force 104 andthe left and right sections 66 and 68 of the suture are being tensioned,a pair of force application members 112 and 114 are pressed againstopposite sides of the suture retainer 50. The force applied against thesuture retainer 50 by the force application members 112 and 114plastically deforms the material of the suture retainer.

The plastic deformation of the suture retainer 50 is effective to causecold flowing of material of the suture retainer. Force indicated byarrows 118 and 120 in FIG. 3, is applied against the suture retainer 50by the force application members 112 and 114. This force is effective tocause flowing of the material of the suture retainer 50 at a temperaturebelow a transition temperature range for the material of the sutureretainer. Although the illustrated force application members 112 and 114have flat force transmitting surfaces, each of the force applicationmembers could have force transmitting surfaces with a configurationcorresponding to the configuration of a portion of a sphere.

The cold flowing of the material of the suture retainer 50 results in acollapsing of the passage 92 (FIG. 2) and in flowing of the material ofthe suture retainer 50 around the sections 66 and 68 of the suture 52.This enables the material of the suture retainer 50 to bond to andobtain a firm grip on the suture 52. The cold flowing of the material ofthe suture retainer 50 occurs at a temperature which is below thetransition temperature of the material forming the suture retainer.

In the illustrated embodiment of the suture retainer 50, the material ofthe suture retainer flows around and grips the portion of the suturewhich was disposed in the passage 92. In addition, the force appliedagainst the turns 82 and 84 by the force application members 112 and 114is sufficient to embed the turns 82 and 84 of the suture 52 in thematerial of the suture retainer 50 to further grip the suture. If theturns 82 and 84 are disposed in grooves in the outside of the sutureretainer, the material of the suture retainer would more firmly grip theportion of the suture 52 forming the turns 82 and 84. If desired,grooves could be formed in the cylindrical side surface of the passage92 to receive the sections 66 and 68 of the suture 52.

A transducer or load cell 124 (FIG. 3) is connected with the forceapplication member 112 to measure the amount of force, indicated by thearrows 118 and 120, which is applied against the suture retainer 50. Adisplay unit 126 is connected with the load cell 124 and provides anoutput indicative of the force being applied against opposite sides ofthe suture retainer 50 by the force application members 112 and 114.After a predetermined minimum force has been applied against the sutureretainer 50 for a predetermined minimum time by the force applicationmembers 112 and 114, an output from the display unit 126 activates anindicator 130 to indicate to a surgeon that the desired plasticdeformation of the suture retainer 50 has occurred. The forceapplication members 112 and 114 can then be withdrawn from the sutureretainer 50.

During the time in which the force application members 112 and 114 areapplying the clamping forces 118 and 120 against opposite sides of thesuture retainer 50, the suture retainer is pressed against the upperside surface 98 of the body tissue 54 with a predetermined force,indicated at 104 in FIG. 3. In addition, a predetermined tension ismaintained in sections 66 and 68 of the suture 52 extending upward fromthe suture retainer 50. Upon disengagement of the force applicationmembers 112 and 114 from the suture retainer 50, the application of thedownward (as viewed in FIG. 3) force 104 against the suture retainer 50is interrupted. The upward tensioning of the sections 66 and 68 of thesuture 52 is also interrupted.

The application of the clamping forces 118 and 120 against oppositesides of the suture retainer 50 causes cold flowing of the material ofthe suture retainer. As this occurs, the material of the suture retainer50 moves between and extends around the portions of the left and rightsections 66 and 68 of the suture 52 disposed in the passage 92 (FIG. 2).Thus, a portion 134 (FIGS. 2 and 4) and a portion 136 of the leftsection 66 of the suture 52 are fully enclosed by the material of thesuture retainer 50. A cold bonding of the material of the sutureretainer 50 with the exterior surfaces of the portions 134 136 of theleft section 66 of the suture retainer securely interconnects thematerial of the suture retainer and the suture 52.

Similarly, the portions 138 and 140 of the right section 68 of thesuture 52 disposed in the passage 92 (FIG. 2) are surrounded by andbonded with the material of the suture retainer 50 (FIG. 4). The mannerin which the material of the suture retainer 50 extends completelyaround and is connected with the length or portion 138 of the rightsection 68 of the suture 52 is illustrated schematically in FIG. 5. Itshould be understood that the permanent deformation of the material ofthe suture retainer 50 occurs as a result of compression of the materialof the suture retainer while the material is at a temperature close tothe temperature of the body tissue 54. This temperature is below thetransition temperature for the material of the suture retainer 50.

Once the suture retainer 50 has been plastically deformed to securelygrip the suture 52, the suture may be knotted if desired. Thus, a knotmay be formed between the portions of the sections 66 and 68 of thesuture 52 which extend upward (as viewed in FIGS. 1-3) from the retainer50. Such a knot would provide additional protection against the sutureworking loose under the influence of varying loads over an extendedperiod of time. Since the suture retainer 50 is disposed between theknot and the body tissue 54, the knot will not reduce the overall forcetransmitting capability of the suture 52. However, it is believed thatforming a knot in the sections 66 and 68 of the suture 52 adjacent tothe upper end of the suture retainer 50 will not be necessary.

The suture retainer 50 may be formed of many different materials.However, it is believed that it will be preferred to form the sutureretainer 50 of a biodegradable polymer. One biodegradable polymer whichmay be utilized is polycaperlactone. Alternatively, the suture retainer50 could be formed of polyethylene oxide terephthalate or polybutyleneterephthalate. It is also contemplated that other biodegradable orbioerodible copolymers could be utilized if desired.

Although it is preferred to form the suture retainer 50 of abiodegradable material, the suture retainer could be formed of amaterial which is not biodegradable. For example, the suture retainercould be formed of an acetyl resin, such as “Delrin” (trademark).Alternatively, the suture retainer 50 could be formed of apara-dimethylamino-benzenediazo sodium sulfonate, such as “Dexon”(trademark).

It is preferred to effect the cold flowing of the material of the sutureretainer 50 without the addition of heat. However, it is contemplatedthat the suture retainer 50 could be heated to a temperature which issomewhat above the temperature of the body tissue 54. If desired, heatcould be transmitted to the suture retainer 50 through the forceapplication members 112 and 114 (FIG. 3). Although the suture retainer50 may be heated, the suture retainer would be maintained at atemperature below the transition temperature for the material of thesuture retainer.

In the illustrated embodiment of the invention, the suture 52 isseparate from the suture retainer 50. However, one of the sections 66 or68 of the suture 52 could be fixedly connected with the suture retainer50. This could be accomplished with a suitable fastener or by formingthe suture 52 integrally as one piece with the suture retainer. Thiswould result in the suture retainer 50 sliding along only one of thesections 66 or 68 of the suture 52.

The suture 52 may be formed of natural or synthetic materials. Thesuture 52 may be a monofilament or may be formed of a plurality ofinterconnected filaments. The suture 52 may be biodegradable ornonbiodegradable. It may be preferred to form the suture 52 of the samematerial as the suture retainer 50. However, the suture 52 could beformed of a material which is different than the material of the sutureretainer.

The use of the suture retainer 50 eliminates the necessity of forming aknot in the suture 52. By eliminating the formation of a knot in thesuture 52, the overall force transmitting capability of the suture isincreased. In addition to increasing the overall force transmittingcapability of the suture 52, the suture retainer 50 increases thesurface area on the body tissue 54 (FIG. 1) against which force isapplied by the suture. This tends to minimize any tendency for thesuture 52 to cut or separate the body tissue.

It is believed that it may be preferred to position the left and rightsections 66 and 68 of the suture 52 relative to the body tissue 54(FIG. 1) before winding the two sections of the suture around the sutureretainer 50. However, one of the sections 66 or 68 of the suture 52 maybe wound around the suture retainer 50 before the suture is positionedin the passages 60 and 62 in the body tissue 54. For example, the leftsection 66 of the suture 52 may e wound around the suture retainer 52 toform the bends 72 and 74 and the loop 86 (FIG. 2) while the suture isspaced from the body tissue 54. The right section 68 of the suture isthen inserted through the passages 60 and 62 (FIG. 1) in the body tissue54. The right section 68 of the suture 52 is then wound around thesuture retainer 50 to form the bends 76 and 78 and loop 88 (FIG. 2).

Embodiment of FIGS. 6-8

In the embodiment of the invention illustrated in FIGS. 1-5, completeloops 86 and 88 are formed in the sections 66 and 68 of the suture 52.In the embodiment of the invention illustrated in FIGS. 6-8, partialloops are formed in each of the sections of the suture. Since theembodiment of the invention illustrated in FIGS. 6-8 is similar to theembodiment of the invention illustrated in FIGS. 1-5, similarterminology will be utilized to identify similar components. It shouldbe understood that one or more features of the embodiment of theinvention illustrated in FIGS. 1-5 may be used with the embodiment ofthe invention illustrated in FIGS. 6-8.

A suture retainer 150 is utilized to secure a suture 52 against movementrelative to body tissue. The suture 52 has sections 66 and 68 whichengage body tissue in the same manner as previously described inconjunction with the embodiment of the invention illustrated in FIGS.1-5. Although the suture 52 is illustrated in FIG. 1 in association withsoft body tissue, it is contemplated that the suture 52 could beutilized in association with hard body tissue and/or one or more sutureanchors.

The suture retainer 150 includes a rectangular base or body section 152and a movable post or locking section 154. The post or locking section154 is integrally formed as one piece with the base 152. The post orlocking section is hingedly connected with the base 152 at a connection156. The post 154 is pivotal relative to the base at the connection 156in the manner indicated schematically by the arrow 158 in FIG. 6.

The base 152 has a central groove 162 which is aligned with the post154. The groove 162 has a rectangular cross sectional configuration. Thegroove 162 has a cross sectional area which is greater than the crosssectional area of the post 154. In the illustrated embodiment of thesuture retainer 150, the post 154 and groove 162 both have a rectangularcross sectional configuration. However, the post and groove could have adifferent cross sectional configuration if desired. For example, thepost 154 and groove 162 could have a semi-circular cross sectionalconfiguration.

The base 152 has a pair of flat rectangular upper (as viewed in FIGS. 6and 7) side surfaces 166 and 168. The flat side surfaces 166 and 168extend in opposite directions from the groove 162 and extend parallel toa flat rectangular bottom surface 170. The suture retainer 150 is formedfrom a single piece of a biodegradable polymer, such aspolycaperlactone. Of course, other biodegradable or bioerodiblecopolymers could be utilized to form the suture retainer 150. It iscontemplated that the suture retainer 150 may be formed of materialswhich are not biodegradable.

When the suture retainer 150 is to be utilized to hold the sections 66and 68 of the suture 52 against movement relative to body tissue, thepost 154 is pivoted from its initial or extended position, shown in FIG.6, to its engaged or locking position, shown in FIG. 7. As the post 154is pivoted to the engaged position of FIG. 7, a flat side surface 174 ofthe post is pressed against the sections 66 and 68 of the suture toforce the sections into the groove 162. The post is effective to clampor hold the sections 66 and 68 of the suture 52 against movementrelative to the base 152 upon movement of the post to the engagedposition shown in FIG. 7.

Once the post 154 has been moved to the engaged position shown in FIG.7, the base 152 is bent from the flat orientation of FIGS. 6 and 7 tothe folded orientation of FIG. 8. Once the base 152 has been folded, apair of force application members 112 and 114 engage opposite sides ofthe bottom or outer surface 170 of the base. The force applicationmembers 112 and 114 are then pressed toward each other, in the mannerindicated schematically by the arrows 118 and 120 in FIG. 8, to applypressure against the suture retainer 150.

At this time, the suture retainer 150 is at a temperature below thetransition temperature of the material forming the suture retainer.Thus, the suture retainer 150 is at a temperature which is approximatelythe same as the temperature of the body tissue relative to which thesuture retainer 150 is being utilized to secure the suture 52. The forceapplied against the suture retainer 150 by the force application members112 and 114 plastically deforms the material of the suture retainer.This results in a cold flowing of the material of the suture retainer150 under the influence of the force applied against the suture retainerby the force application members 112 and 114.

A transducer or load cell 124 measures the force 118 and 120 appliedagainst the base 152 of the suture retainer 150. The load cell 124provides an output signal to a display unit 126. The output signalprovided by the transducer 124 corresponds to the magnitude of the forceapplied against opposite sides of the suture retainer 150 by the members112 and 114.

After a predetermined minimum force has been applied against oppositesides of the suture retainer 150 for a sufficient period of time toeffect a cold flowing of the material of the suture retainer, an outputsignal from the display unit 126 activates an indicator 130. The outputfrom the indicator 130 indicates to a surgeon and/or other medicalpersonnel that the force has been applied against opposite sides of thesuture retainer 150 by the force application members 112 and 114 for aperiod of time sufficient to cause cold flowing of the material of thesuture retainer. The cold flowing of the material of the suture retainer150 results in a secure interconnection between the material of thesuture retainer 150 and the sections 66 and 68 of the suture 52.

In the embodiment of the invention illustrated in FIGS. 6-8, the suture52 is separate from the suture retainer 150. However, the suture 52could be fixedly connected to or integrally formed as one piece with thesuture retainer 150. For example, the base 152 could be integrallyformed with the section 66 of the suture 52 if desired.

Embodiment of FIGS. 9-12

In the embodiment of the invention illustrated in FIGS. 1-5, thesections 66 and 68 of the suture 52 extend through a passage formed in aspherical suture retainer 50. In the embodiment of the inventionillustrated in FIGS. 9-12, the sections of the suture extend along agroove formed in the outside of a suture retainer. Since the embodimentof the invention illustrated in FIGS. 9-12 is similar to the embodimentof the invention illustrated in FIGS. 1-5, similar terminology will beutilized to identify similar components. It should be understood thatone or more features of the embodiments of the invention illustrated inFIGS. 1-8 may be used with the embodiment of the invention illustratedin FIGS. 9-12.

A suture retainer 180 (FIG. 9) is utilized to secure a suture 52 againstmovement relative to body tissue 54. Although the body tissue 54 is softbody tissue, it is contemplated that the suture retainer 180 could beutilized to secure the suture 52 against movement relative to hard bodytissue, such as bone. The suture retainer 180 may be used either with orwithout a suture anchor.

The suture retainer 180 has a cylindrical main section or body 184. Thebody 184 has a cylindrical outer side surface 186. Flat circular endsurfaces 188 and 190 extend perpendicular to a longitudinal central axisof the cylindrical side surface 186. In the illustrated embodiment ofthe suture retainer 180, the body 184 is cylindrical and has a linearlongitudinal central axis. If desired, the body 184 could be rectangularand/or have a nonlinear longitudinal central axis.

A helical groove 194 is formed in the body 184. The helical groove 194has a constant pitch. Therefore, turns of the groove 194 are equallyspaced. However, if desired, the pitch of the turns of the groove 194could vary along the length of the body 184.

The helical groove 194 has a central axis which is coincident with thecentral axis of the body 184 and cylindrical outer side surface 186 ofthe suture retainer 180. A radially inner portion of the helical groove194 defines a right circular cylinder which is coaxial with the outerside surface 186 of the body 184. However, the radially inner portion ofthe helical groove 194 could define a right circular cone or otherconfiguration if desired.

The left and right sections 66 and 68 of the suture 52 extend throughthe groove 194 and around body tissue 54. It is believed that it will beadvantageous to provide the helical groove 194 with retainers or bridgesections 198 and 200 which extend across the open ends of the helicalgroove. The bridge sections 198 and 200 are integrally formed as onepiece with the body 184. The bridge sections 198 and 200 prevent thesections 66 and 68 of the suture 52 from pulling out of the helicalgroove 194 during positioning of the suture retainer 180 in a humanpatient's body. However, the bridge sections 198 and 200 may be omittedif desired.

The helical groove 194 has a generally U-shaped cross sectionalconfiguration (FIG. 10). Thus, the helical groove 194 has an open mouthor entrance 204. A pair of side surfaces 206 and 208 slope radiallyinward and axially upward (as viewed in FIGS. 9 and 10) from theentrance 204. An arcuate bottom surface 210 of the groove 194 extendsbetween the side surfaces 206 and 208.

The section 66 of the suture 52 is disposed in engagement with thebottom surface 210 of the helical groove 194. The section 68 of thesuture 52 is disposed in engagement with the section 66 of the suture(FIG. 10). If desired, the size of the arcuate bottom surface 210 of thegroove 194 could be increased to enable both sections 66 and 68 of thesuture 52 to engage the bottom surface.

The groove 194 may be provided with a configuration similar to theconfiguration shown in FIG. 11. Thus, in FIG. 11, the side surfaces 206and 208 of the helical groove 194 extend inward from the open entrance204 to an arcuate bottom surface 210 which forms a major portion of acircle. The bottom surface 210 of FIG. 11 defines a recess 214 in whichthe two sections 66 and 68 of the suture are disposed. It is believedthat the bridge sections 198 and 200 will probably be omitted with theembodiment of the groove 194 illustrated in FIG. 11.

The cylindrical body 184 of the suture retainer 180 is molded from asingle piece of a biodegradable polymer. For example, the body 184 ofthe suture retainer 180 may be molded from polycaperlactone.Alternatively, the body 184 of the suture retainer 180 could be moldedof polyethylene oxide terephthalate or polybutylene terephthalate. Ofcourse, the body 184 of the suture retainer 180 could be molded as onepiece of other biodegradable or bioerodible copolymers if desired.Although it is preferred to form the body 184 of biodegradablematerials, the body could be formed of materials which are notbiodegradable. For example, the body 184 could be formed of “Delrin”(trademark).

The left and right sections 66 and 68 (FIG. 9) of the suture 52 areinserted into the helical groove 194 in the body 184 of the sutureretainer 180. At this time, the body 184 of the suture retainer 180 isspaced from the body tissue 54. It is believed that insertion of theleft and right sections 66 and 68 of the suture 52 into the helicalgroove 194 will be facilitated if the bridge sections 198 and 200 areomitted. However, if the bridge sections 198 and 200 are omitted,difficulty may be encountered in maintaining the sections 66 and 68 ofthe suture 52 in the helical groove 194.

As the left and right sections 66 and 68 of the suture 52 are insertedinto the helical groove 194 (FIG. 9), the sections of the suture arewrapped around the body 184 of the suture retainer 180. As this occurs,a plurality of helical loops are formed in the left and right sections66 and 68 of the suture 52. Once the suture 52 has been inserted intothe helical groove 194, a plurality of circular turns are maintained inthe left and right sections 66 and 68 of the suture 52 by the helicalgroove 194. Therefore, a continuous series of smooth arcuate bends,which are free of stress inducing discontinuities, is maintained in thesuture 52 by the helical groove 194.

After the suture 52 has been inserted into the helical groove 194, thesuture retainer 180 is moved along the suture toward the body tissue 54(FIG. 9). During this movement of the suture retainer 180 along thesuture 52, the left and right sections 66 and 68 of the suture aretensioned. The radially inward and axially upward sloping configurationof the helical groove 194 (FIGS. 10 and 11) results in the left andright sections 66 and 68 of the suture being pulled toward the arcuatebottom surface 210 of the groove. This results in the body 184 of thesuture retainer 180 maintaining the helical loops in the left and rightsections 66 and 68 of the suture 52 as the suture retainer 180 movestoward the body tissue 54.

As the suture retainer 180 moves toward the body tissue 54 (FIG. 9), theleft and/or right sections 66 and 68 of the suture 52 slide along thearcuate bottom surface 210 (FIG. 10) of the groove 194. The groove 194imparts a helical configuration to the portion of the suture 52 disposedin the groove. As the body 184 of the suture retainer 180 moves downwardtoward the body tissue 54, the portion of the suture 52 having a helicalconfiguration moves downward toward the body tissue.

As the suture retainer 180 is slid along the tensioned sections 66 and68 of the suture 52, the tensioning force in the suture pulls the suturetoward the bottom surface 210 of the helical groove 194. Thebiodegradable copolymer forming the body 184 of the suture retainer 180has a low coefficient of friction. This minimizes the force 220 requiredto move the suture retainer along the left and right sections 66 and 68of the suture 52 toward the body tissue 54.

The suture retainer 180 is moved along the taut left and right sections66 and 68 of the suture 52 until the leading end surface 190 of the body184 of the suture retainer 180 engages the body tissue 54 (FIG. 9). Theforce 220 is then increased to a predetermined magnitude whilemaintaining a predetermined tension in the left and right sections 66and 68 of the suture 52. This results in the suture 52 being pulledtightly around the body tissue and exerting a predetermined forceagainst the body tissue.

It is contemplated that the magnitude of the force 220 (FIG. 9) withwhich the suture retainer 190 is pressed against the body tissue 54 willbe measured to be certain that the force has a desired magnitude. Theforce 220 may be measured with a suitable transducer, such as a loadcell or a force measuring device having a spring which is compressed toa predetermined extent by the application of the desired force againstthe body tissue 54. Rather than engaging the body tissue 54 directlywith the leading end surface 190 of the suture retainer 180, a suitableforce transmitting member, such a button, could be provided between thesuture retainer and the body tissue.

While the suture retainer 180 is being pressed against the body tissue54 with the predetermined force 220 and the sections 66 and 68 of thesuture 52 are being tensioned with a predetermined force, the left andright sections 66 and 68 of the suture 52 are gripped by plasticallydeforming the material of the suture retainer. To plastically deform thematerial of the suture retainer, a plurality of force applicationmembers 224, 226 and 228 (FIG. 12) are pressed against the cylindricalouter side surface 186 of the suture retainer 180. Since the outer sidesurface 186 of the suture retainer 180 has a cylindrical configuration,the force application members 224, 226 and 228 have an arcuateconfiguration and are formed as portions of a circle. However, the forceapplication members 224, 226 and 228 could have the flat configurationof the force application members 112 and 114 of FIG. 3.

The force application members 224, 226 and 228 are pressed against theouter side surface 186 of the suture retainer 180 with a predeterminedforce, indicated by the arrows 232 in FIG. 12. This force has amagnitude and is applied for a length of time sufficient to cause coldflowing of the material of the body 184 of the suture retainer 180. Theplastic deformation of the material of the body 194 of the sutureretainer 180 results in the helical groove 194 being collapsed and thematerial of the suture retainer being pressed against the left and rightsections 66 and 68 of the suture 52. The resulting cold bonding of thematerial of the suture retainer 180 with the left and right sections 66and 68 of the suture 52 secures in the suture retainer against movementrelative to the suture.

The cold flowing of the material of the body 184 of the suture retainer180 occurs with the body of the suture retainer at substantially thesame temperature as the temperature of the body tissue 54 (FIG. 9).Thus, the cold flowing of the material of the body 184 of the sutureretainer 180 occurs at a temperature below the transition temperature ofthe material forming the body 184 of the suture retainer 180. However,if desired, some heat may be added to the body 184 to facilitate plasticdeformation of the body of the suture retainer 180.

The suture retainer 180 eliminates the necessity of forming a knot inthe suture 52. The formation of a knot in the suture 52 would cause astress concentration in the suture and would decrease the overall forcetransmitting capability of the suture. By eliminating the knot, theoverall force transmitting capability of the suture 52 is increased.However, if desired, a knot could be formed in the sections 66 and 68 ofthe suture 52 at a location above (as viewed in FIG. 1) the sutureretainer 180. Since the suture retainer 180 would be disposed betweenthis knot and the body tissue 54, the knot would not decrease theoverall force transmitting capability of the suture 52.

In the embodiment of the invention illustrated in FIGS. 9-12, a singlehelical groove 194 is formed in the body 184 of the suture retainer 180.It is contemplated that a pair of spaced apart helical grooves could beformed in the body 184 of the suture retainer 180. If this was done, thetwo helical grooves would be wrapped in the same direction around thebody 184 of the suture retainer 180 and would be offset from each otherby 180N about the circumference of the cylindrical body of the sutureretainer. The left section 66 of the suture 52 would be disposed in oneof the helical grooves and the right section 68 of the suture would bedisposed in the other helical groove.

By having a pair of spaced apart helical grooves in the body 184 of thesuture retainer 180, in the manner set forth in the preceding paragraph,the left and right sections 66 and 68 of the suture 52 would exit fromthe lower (as viewed in FIG. 9 end of the suture retainer atdiametrically opposite locations on the circular end surface 190. Thisembodiment of the suture retainer 180 would have the advantage of havinga relatively large area of engagement with the body tissue 54. Thus, thetension in the suture would press the flat circular end surface 190 onthe suture retainer against the body tissue.

In the illustrated embodiment of the invention, the suture 52 isseparate from the suture retainer 180. However, if desired, the suture52 could be fixedly connected with or integrally formed as one piecewith the suture retainer. For example, the left section 66 of the suture52 could be fixedly connected with the body 184 of the suture retainer180 by a suitable fastener. If this was done, only the right section 68of the suture 52 would be received in the groove 194.

Embodiment of FIGS. 13-16

In the embodiment of the invention illustrated in FIGS. 9-12, the leftand right sections 66 and 68 of the suture 52 are wrapped in the samedirection around the cylindrical body 184 of the suture retainer 180. Inthe embodiment of the invention illustrated in FIGS. 13-16, the sectionsof the suture are wrapped in opposite directions around a conical bodyof a suture retainer. Since the embodiment of the invention illustratedin FIGS. 13-16 is similar to the embodiment of the invention illustratedin FIGS. 9-12, similar terminology will be utilized to identify similarcomponents. It should be understood that one or more features of theembodiments of the invention illustrated in FIGS. 1-12 may be used withthe embodiments of the invention illustrated in FIGS. 13-16.

A suture 52 (FIG. 13) has left and right sections 66 and 68 which arewrapped in opposite directions around a conical body 242 of a sutureretainer 244. Thus, as viewed from above, the left section 66 of thesuture 52 is wrapped in a counterclockwise direction around the body 242of the suture retainer 244. The right section 68 of the suture 52 iswrapped in a clockwise direction around the body 242 of the sutureretainer 244.

The left and right sections 66 and 68 of the suture 52 are wrapped forapproximately 1½ turns around the body 242 of the suture retainer 244.Therefore, the left section 66 of the suture 52 moves from the left sideof the upper end (as viewed in FIG. 13) of the body 242 of the sutureretainer 244 to the right side of the lower end of the body of thesuture retainer. Similarly, the right section 68 of the suture 52 movesfrom the upper right side of the body 242 of the suture retainer 244 tothe lower left side of the body of the suture retainer.

If the two sections 66 and 68 of the suture 52 were wrapped around thebody 242 of the suture retainer 244 for complete turns, the sections ofthe suture would be on the same side of the body 242 at the top andbottom of the suture retainer. For example, if the suture 52 was wrappedtwo complete turns around the body 242, the left section 66 of thesuture 52 would be disposed at the left side of both the upper and lowerends of the body 242. Similarly, the right section 68 of the suture 52could be disposed at the right side of both the upper and lower ends ofthe body 242 of the suture retainer.

The body 242 of the suture retainer 244 is formed as a portion of aright circular cone. The body 242 of the suture retainer 244 has anouter side surface 248 with an axially downward (as viewed in FIG. 13)and radially inward tapering configuration. The conical body 242 of thesuture retainer 244 has parallel circular end surfaces 252 and 254 whichextend perpendicular to a longitudinal central axis of the conical body.The circular end surfaces 252 and 254 are disposed in a coaxialrelationship. The upper end surface 252 has a larger diameter than thelower end surface 254.

A pair of helical grooves 258 and 260 (FIGS. 13-16) are formed in theconical body 242. The helical grooves 258 and 260 have a spiralconfiguration with a central axis which is coincident with the centralaxis of the conical body 242. Thus, the diameter of the turns of thegrooves 258 and 260 progressively decreases as the grooves extenddownward (as viewed in FIG. 13) from the upper end surface 252 to thelower end surface 254. The helical grooves 258 and 260 have the samepitch.

The helical grooves 258 and 260 are wrapped in opposite directionsaround the conical body 242 of the suture retainer 244. Thus, as viewedfrom above, the helical groove 258 is wrapped in a counterclockwisedirection around the body 242 of the suture retainer 244. The helicalgroove 260 is wrapped in a clockwise direction around the body 242 ofthe suture retainer 244.

The helical grooves 258 and 260 are offset by 180°. Thus, the helicalgroove 258 beings at the upper left (as viewed in FIG. 13) side of thebody 242 and the helical groove 260 begins at the upper right side ofthe body 242. The entrances to the helical grooves 258 and 260 aredisposed at diametrically offset locations on the circular upper endsurface 252 of the body 242. The helical groove 258 ends at the lowerright (as viewed in FIG. 13) side of the body 242. The helical groove260 ends at the lower left side of the body 242. The exits from thehelical grooves 258 and 260 are disposed at diametrically offsetlocations on the circular lower end surface 254 of the body 242. Thisresults in the relatively large lower end surface 254 of the body 242being disposed between the left and right sections 66 and 68 of thesuture 52 and exposed to body tissue.

The groove 258 has an axially upward and radially inward slopingconfiguration (FIG. 14). The groove 258 has a helical open mouth orentrance 264. The groove 258 has a pair of axially upward and radiallyinward sloping side surfaces 266 and 268. The side surfaces 266 and 268are interconnected by an arcuate bottom surface 270. The groove 258 hasthe same depth and cross sectional configuration throughout the extentof the groove.

Although only the groove 258 is illustrated in FIG. 14, it should beunderstood that the groove 260 has the same cross sectionalconfiguration as the groove 258. The two grooves 258 and 260 extendbetween the opposite end surfaces 252 and 254 of the conical body 242.It is contemplated that the grooves 258 and 260 could have a differentcross sectional configuration if desired. For example, the grooves 258and 260 could have the cross sectional configuration shown in FIG. 11 ifdesired.

The grooves 258 and 260 intersect on opposite sides of the conical body242 in the manner illustrated in FIGS. 15 and 16. At the intersectionsbetween the grooves 258 and 260, the left and right sections 66 and 68of the suture 52 overlap (FIG. 16). The number of intersections ofgrooves 258 and 260 will vary as a direct function of the number ofturns of the grooves 258 and 260 around the body 242.

Bridge sections 274 and 276 (FIG. 13) are provided across opposite endsof the groove 258 to facilitate in retaining the suture section 66 inthe groove. Similarly, bridge sections 278 and 280 are provided acrossopposite ends of the groove 260 to facilitate in retaining the suturesection 68 in the groove 260. If desired, the bridge sections 274, 276,278 and 280 could be omitted.

In addition to the conical body 242, the suture retainer 244 includes acylindrical sleeve 284 (FIG. 13). The tubular sleeve 284 has acylindrical outer side surface 286 and a conical inner side surface 288.The inner and outer side surfaces 286 and 288 are disposed in coaxialrelationship. The conical inner side surface 288 of the sleeve 284tapers axially inward and downward (as viewed in FIG. 13) at the sameangle as does the conical outer side surface 248 of the body 242.

Although the conical inner side surface 288 of the sleeve 284 has beenschematically illustrated in FIG. 13 as having an inside diameter whichis greater than the outside diameter of the conical body 242, it iscontemplated that the conical body 242 will have substantially the samediameter as the inner side surface 288 of the sleeve 284. Therefore,when the circular end surface 252 on the conical body 242 is axiallyaligned with an annular end surface 292 on the sleeve 284 (as shown inFIG. 13), the outer side surface 248 on the conical body 242 will bedisposed in abutting engagement with the inner side surface 288 on thesleeve 286. Of course, if the conical inner side surface 288 of thesleeve 284 has a larger diameter than the conical outer side surface 248of the body 242, axially downward (as viewed in FIG. 13) movement of theconical body 242 relative to the sleeve 284 will result in abuttingengagement between the inner side surface 288 of the sleeve and theouter side surface 248 of the conical body.

The conical body 242 and the sleeve 284 are both formed of abiodegradable polymer, such as polycaperlactone. However, the conicalbody 242 and the sleeve 284 could be formed of polyethylene oxideterephthalate or polybutylene terephthalate if desired. Otherbiodegradable or bioerodible copolymers could be utilized if desired. Itis contemplated that it may be desired to form the conical body 242 andsleeve 284 of a polymer which is not biodegradable. The conical body 242and sleeve 284 could be formed of two different materials if desired.

When the suture retainer 244 is to be positioned in a human patient'sbody, the left and right sections 66 and 68 of the suture are firstinserted through the open center of the sleeve 284. The sections 66 and68 of the suture 52 are then wrapped around the conical body 242 in thegrooves 258 and 260. The sleeve 284 may then be moved along the suture252 to the desired position in a patient's body.

It is believed that it will be preferred to position the left and rightsections 66 and 68 of the suture 52 relative to the body tissue beforewinding the two sections of the suture around the body 242. However, oneof the sections 66 or 68 of the suture 52 may be wound around the body242 and inserted through the sleeve 284 before the suture is positionedrelative to the body tissue. After the suture 52 has been positionedrelative to the body tissue, the other section of the suture would beinserted through the sleeve 284 and wound around the body 242.

When the suture 52 has been positioned relative to the body tissue andsuture retainer 244, the sections 66 and 68 of the suture 52 aretensioned as a force 296 (FIG. 13) is applied to the conical body 242.The force 296 is sufficient to cause the conical body 242 of the sutureretainer 244 to slide axially along the sections 66 and 68 of the suturetoward the sleeve 284. As this occurs, the outer side surface 248 on theconical body 242 moves into engagement with the inner side surface 288on the sleeve 284. The force 296 is then effective to press the outerside surface 248 on the conical body 242 firmly against the inner sidesurface 288 of the sleeve.

The force 296 is also effective to press both the end surface 254 of theconical body 242 and an annular end surface 300 of the sleeve 284against the body tissue. While the left and right sections 66 and 68 ofthe suture are tensioned, the force 296 is increased. After the sutureretainer 244 has been pressed against the body tissue with apredetermined force 296 sufficient to cause the suture 52 to grip thebody tissue with a desired tension, force applicator members, similar tothe force applicator members 224, 226 and 228 of FIG. 12, compress thesleeve 284. The manner in which force is applied against the sleeve 284is indicated schematically by arrows 302 and 304 in FIG. 13. If desired,one or more axial slot may be provided through a portion of the sleeve284 to facilitate compression of the sleeve.

The force applied against the sleeve 284, indicated schematically at 302and 304, causes radially inward plastic deformation of the sleeve. Thisforce is transmitted through the sleeve to the conical body 242. Theforce transmitted to the conical body 242 causes a collapsing of thegrooves 258 and 260. As the grooves 258 and 260 collapse, the materialof the conical body 242 is plastically deformed and firmly grips orbonds to the outer side surfaces of the left and right sections 66 and68 of the suture 52. The sleeve 284 bonds to the material of the conicalbody 242.

The sleeve 284 and conical body 242 of the suture retainer 244 are at atemperature below the transition temperature of the material forming thesleeve and conical body when they are compressed by the force indicatedschematically at 302 and 304 in FIG. 13. This results in cold flowing ofthe material of both the sleeve 284 and the suture retainer 244 underthe influence of the force 302 and 304. The force 302 and 304 ismaintained at a predetermined magnitude for a time sufficient to resultin cold plastic deformation of the material of the sleeve 284 andconical body 242. This plastic deformation or cold flow of the materialof the sleeve 284 and conical body 242 occurs at a temperature which issubstantially the same as the temperature of the body tissue with whichthe suture 52 is connected.

If desired, cold flowing of the material of the sleeve 284 and conicalbody 244 could be promoted by the addition of heat. Thus, the sleeve 284and conical body 244 may be preheated before being moved into engagementwith the body tissue. If desired, heat could be transmitted to thesleeve 284 and conical body 242 during application of he force 302 and304. During the application of the force 302 and 304 to the sleeve 284,both the conical body 242 and sleeve 284 are at a temperature below thetransition temperature of the material of the conical body and sleeve.

Once the suture retainer 284 has been plastically deformed to securelygrip the suture 52, the suture may be knotted. Thus, a knot may beformed in the upper (as viewed in FIG. 13) end portions 66 and 68 ofsuture 52. The knot would pull the sections 66 and 68 of the suturefirmly against the upper side surface 252 of the conical body 242. Thisknot would not decrease the overall force transmitting capability of thesuture 52 since the suture retainer 244 would be disposed between theknot and the body tissue. Although such a knot would provide additionalassurance that the suture will not work loose, it is believed that theknot is not necessary.

The tension in the suture 52 will press the annular end surface 300 onthe sleeve 284 and the circular end surface 254 on the conical body 242against the body tissue. Due to the relative large combined area of theend surfaces 254 and 300, the tension forces in the suture 52 will beapplied to a relatively large area on the body tissue by the sutureretainer 244. Since the suture retainer 244 applies force to arelatively large surface area on the body tissue and since the overallstrength of the suture 52 is not impaired by the suture retainer 244,relatively large forces can be transmitted through the suture to thebody tissue.

In the embodiment of the invention illustrated in FIGS. 13-16, thehelical grooves 258 and 260 cross. This results in the left and rightsections 66 and 68 of the suture 52 being disposed in overlappingengagement at the intersections between the grooves 258 and 260. Theoverlapping engagement of the left and right sections 66 and 68 of thesuture 52 increases the resistance of the suture retainer 244 toslipping of one section of the suture relative to the other section ofthe suture.

Embodiments of FIGS. 17-19

In the embodiment of the invention illustrated in FIGS. 13-16, thecentral axis of the conical body 242 of the suture retainer 244 extendsalong the sections 66 and 68 of the suture 52. In the embodiments of theinvention illustrated in FIGS. 17-19, a central axis of a circular bodyof the suture retainer extends transverse to the longitudinal axis ofthe suture during movement of the suture retainer toward the bodytissue. Since the suture retainer of the embodiments of the inventionillustrated in FIGS. 17-19 is similar to the suture retainer of theembodiment of the invention illustrated in FIGS. 13-16, similarterminology will be utilized to identify similar components. It shouldbe understood that one or more features of the embodiments of theinvention illustrated in FIGS. 1-16 may be used with the embodiments ofthe invention illustrated in FIGS. 17-19.

A suture retainer 312 (FIGS. 17 and 18) includes a cylindrical housing314 and a rotatable cylinder 316. The housing 314 encloses the rotatablecylinder 316. The rotatable cylinder 316 has a central axis which iscoincident with the central axis of the cylindrical housing 314.

The cylinder 316 is supported for rotation relative to the housing 314by bearing sections 320 and 322 (FIG. 17). The bearing sections 320 and322 are integrally formed as one piece with the housing 314. The bearingsections 320 and 322 have a conical configuration and engage conicalrecesses formed in opposite ends of the rotatable cylinder 316. Thebearing sections 320 and 322 support the cylinder 316 in a coaxialrelationship with the housing 314.

Left and right sections 66 and 68 of the suture 52 extend into thehousing 314 through cylindrical openings 326 and 328. The sections 66and 68 of the suture 52 extend from the housing 314 through openings 330and 332. The openings 326, 328, 330 and 332 have parallel central axeswhich extend tangentially to the cylinder 316.

The left section 66 of the suture 52 extends through the opening 326into the housing 314. The left section 66 of the suture 52 is wrapped ina clockwise direction (as viewed in FIG. 18) around the cylinder 316 andextends from the housing 314 through the opening 330. Similarly, theright section 68 (FIG. 17) of the suture 52 extends into the housing 314through the opening 328. The right section 68 of the suture 52 iswrapped in a counterclockwise direction, as viewed in FIG. 18, aroundthe cylinder 316. The turns in the left and right sections 66 and 68 inthe suture 52 are axially spaced apart along the cylindrical outer sidesurface of the cylinder 316. If desired, helical grooves may be providedin the cylinder 316 to receive the turns of the left and right sections66 and 68 of the suture.

The cylindrical housing 314 is formed of a biodegradable polymericmaterial. The cylinder 316 is also formed of a biodegradable polymericmaterial. However, the material of the cylinder 316 is harder than thematerial of the housing 314. The material of the cylinder 316 has alower coefficient of friction than the material of the housing 314. Thematerial of the housing 314 is easier to plastically deform than thematerial of the cylinder 316. Of course, the housing and cylinder 314and 316 may be formed of the same material which may be biodegradable(polycaperlactone) or may not be biodegradable.

When the suture retainer 312 is to be positioned relative to body tissue(not shown), the left and right sections 66 and 68 of the suture aretensioned. The housing 312 is then pushed downward (as viewed in FIGS.17 and 18) in the manner indicated schematically by an arrow 336 in FIG.18. As this occurs, the turns or wraps of the sections 66 and 68 of thesuture slide along a cylindrical outer side surface of the rotatablecylinder 316. The oppositely wound loops in the sections 66 and 68 ofthe suture 52 move downward along the suture toward the body tissue asthe retainer 312 moves downward along the suture toward the body tissue.

Although there will be some rotational movement of the cylinder 316relative to the housing 314, the position of the cylinder 316 relativeto the housing 314 remains substantially constant during a major portionof the movement of the suture retainer 312 along the suture 52 towardthe body tissue. This is because the left and right sections 66 and 68of the suture are wrapped in opposite directions around the cylinder316. This results in the portion of the loop in the left section 66 ofthe suture tending to rotate the cylinder 316 in a counterclockwisedirection (as viewed in FIG. 18). At the same time, the loop formed inthe right section 68 of the suture 52 tends to rotate the cylinder 316in a clockwise direction (as viewed in FIG. 18).

Since the two sections 66 and 68 of the suture 52 tend to urge thecylinder 316 to rotate in opposite directions, the cylinder tends toremain more or less stationary relative to the housing 314. The loops inthe left and right sections 66 and 68 of the suture 52 slide along thecylindrical outer side surface of the cylinder 316. However, it shouldbe understood that there will be some rotational movement of thecylinder 316 relative to the housing 314 as the suture retainer 312 ismoved toward the body tissue.

Once the housing 314 of the suture retainer 312 is moved into engagementwith the body tissue, the tension is maintained in the sections 66 and68 of the suture 52. The force 336 (FIG. 18) pressing the sutureretainer 312 against the body tissue is increased. The suture retainer312 is pressed against the body tissue with a force, indicatedschematically by the arrow 336 in FIG. 18, which is sufficient toprovide a desired tension in the portion of the suture 52 engaging thebody tissue.

The material of the suture retainer 312 is then plastically deformed.The plastic deformation of the suture retainer 312 is accomplished byapplying force against opposite sides of the housing 314 with a pair offorce application members 340 and 342 (FIG. 18). The force appliedagainst the suture retainer 312 by the force application members 340 and342 presses the material of the housing 314 against the sections 66 and68 of the suture and the cylinder 316 by cold flowing material of thehousing.

A large gap has been shown between the cylindrical outer side surface ofthe cylinder 316 and a cylindrical inner side surface of the housing 314in FIG. 18. However, it should be understood that this annular gap willbe relatively small so that the material of the housing 314 can readilycold flow into engagement with the turns of the sections 66 and 68 ofthe suture 52 and cylinder 316. The force applied against the housing314 also plastically deforms and causes cold flowing of the material ofthe cylinder 316 to provide a secure bond or grip between the materialof the cylinder 316 and the suture 52.

A transducer or load cell 346 is associated with the force applicationmember 342 and provides an output to a display unit 348. After apredetermined minimum force has been applied to the suture retainer 312by the force application members 340 and 342 for a predetermined minimumlength of time, an output from the display unit 348 to an indicator 350activates the indicator to provide a signal that the desired plasticdeformation of the suture retainer 312 has been obtained.

If desired, a knot may be tied between the left and right sections 66and 68 of the suture 52 adjacent to a side of the housing 314 oppositefrom a side of the housing which is pressed against the body tissue bythe suture. The knot would be pulled tight against the housing at alocation between the openings 326 and 328. Since the suture retainer 312is between the knot and the body tissue, the knot would not impair theforce transmitting capability of the suture 52.

In FIGS. 17 and 18, the sections 66 and 68 of the suture 52 are wrappedin opposite directions around the cylinder 316. This results inoffsetting forces being applied to the cylinder 316 by the turns in thesections 66 and 68 of the suture 52 during movement of the sutureretainer 312 along the suture toward the body tissue. In FIG. 19, theleft and right sections 66 and 68 of the suture 52 are wrapped in thesame direction around the cylinder 316. This results in the turns orloops in the sections 66 and 68 of the suture 52 applying force to thecylinder 316 urging the cylinder to rotate in the same direction duringmovement of the suture retainer 312 along the sections 66 and 68 of thesuture toward body tissue. Therefore, when the sections 66 and 68 of thesuture 52 are wrapped in the same direction around the cylinder 316, thecylinder will freely rotate relative to the housing 314 as the sutureretainer 312 is moved along the suture 52 toward the body tissue.

The overall force transmitting capability of the suture 52 is notimpaired by the suture retainer 312. This is because the turns of theloops formed in the left and right sections of the suture 52 around thecylinder 316 do not form stress concentrations in the suture. If a knothad been used to interconnect the left and right sections 66 and 68 ofthe suture 52, in the manner taught by the prior art, the resultingstress concentration would reduce the overall force transmittingcapability of the suture 52.

The cylindrical housing 314 increases the surface area on body tissueagainst which force is applied by tension in the suture 52 after thesuture retainer 312 has been plastically deformed to grip the suture.This increases the amount of force which may be transmitted through thesuture 52 without damaging the body tissue.

Embodiment of FIG. 20

In the embodiment of the invention illustrated in FIGS. 17-19, thecylinder 316 is rotatable relative to the housing 314. In the embodimentof the invention illustrated in FIG. 20, cylinders are fixedly connectedwith the housing. Since the embodiment of the invention illustrated inFIG. 20 is similar to the embodiment of the invention illustrated inFIGS. 17-19, similar terminology will be utilized to identify similarcomponents. It should be understood that one or more features of theembodiments of the invention illustrated in FIGS. 1-19 may be used withthe embodiment of the invention illustrated in FIG. 20.

A suture retainer 356 includes a rectangular housing 358 which enclosesa plurality of cylinders 360, 362, 364 and 366. The cylinders 360-366have parallel central axes which extend parallel to flat rectangularupper and lower side walls 370 and 372 of the housing 358. Opposite endportions of the cylinders 360-366 are fixedly connected with rectangularend walls (not shown) of the housing 358. The central axes of thecylinders 360-366 extend perpendicular to the housing end walls to whichthe cylinders are fixedly connected.

In the embodiment of the invention illustrated in FIG. 20, the cylinders360-366 are formed of a biodegradable material which is relatively hard.The housing 358 is formed of a biodegradable material which isrelatively soft. By forming the housing 358 of a biodegradable materialwhich is relatively soft, plastic deformation of the housing isfacilitated. The relatively hard biodegradable material forming thecylinders 360-366 has a low coefficient of friction. Although it ispreferred to form the cylinders 360-366 and housing 358 of biodegradablematerials having different hardnesses, the cylinders and housing couldbe formed of biodegradable or nonbiodegradable materials having the samehardness if desired.

A suture 52 has left and right sections 66 and 68 which are wrappedaround the cylinders 360-366 in a zig-zag fashion. Thus, the leftsection 66 of the suture 52 is looped around the cylinders 360 and 362.The right section 68 of the suture 52 is looped around the cylinders 364and 366. The cylinders 360 and 362 maintain a pair of smooth, continuousbends in the left section 66 of the suture 52. Similarly, the cylinders364 and 366 maintain a pair of smooth, continuous bends in the rightsection 68 of the suture 52. The smooth, continuous bends in thesections 66 and 68 of the suture 52 are free of stress inducingdiscontinuities. If desired, a greater or lesser number of bends couldbe maintained in the sections 66 and 68 of the suture 52 by a greater orlesser number of cylinders.

In the embodiment of the invention illustrated in FIG. 20, there is asingle partial turn of the left section 66 of the suture around each ofthe cylinders 360 and 362. Similarly, there is a single partial turn ofthe right section 68 of the suture 52 around each of the cylinders 364and 366. If desired, a plurality of turns or loops could be providedaround each of the cylinders 360-366 by the sections 66 and 68 of thesuture 52. For example, the left section 66 of the suture 52 could bewrapped for one complete revolution around the cylinder 360 and thenwrapped for a partial revolution around the cylinder 360 beforeextending to the cylinder 362. Similarly, the right section 68 of thesuture 52 could be wrapped for one complete revolution around thecylinder 366 and then wrapped for a partial revolution around thecylinder 364 before exiting from the housing 358.

After the suture 52 has been wrapped around the cylinders 360-366 in themanner illustrated schematically in FIG. 20, the suture retainer 356 ismoved along the sections 66 and 68 of the suture 52 toward body tissue.As the housing 358 is moved downward (as viewed in FIG. 20), toward thebody tissue, the left and right sections 66 and 68 of the suture 52slide along the outer side surfaces of the cylinders 360-366. As thisoccurs, the cylinders 360-366 cooperate to maintain a plurality of bendsin each of the sections 66 and 68 of the suture 52.

Once the housing 358 has been pressed against the body tissue with apredetermined force 376 while a predetermined tension is maintained inthe left and right sections 66 and 68 of the suture 52, the housing 358is plastically deformed to grip the suture 52. Thus, force, indicated byarrows 380 and 382 in FIG. 20 supplied against a side of the housing 358opposite from the force 376. This force is effective to plasticallydeform the material of the housing and to press the material of thehousing against the cylinders 360-366 and against the sections 66 and 68of the suture 52.

As the forces indicated by the arrows 376, 380 and 382 plasticallydeform the housing 358, the material of the housing cold flows under theinfluence of the force. This cold flow of the material of the housingresults in the left and right sections 66 and 68 of the suture beingfirmly pressed against the cylinders 360-366 to form a solid bond withthe left and right sections 66 and 68 of the suture 52. Since thematerial forming the cylinders 360-366 is relatively hard, compared tothe material forming the housing 358, the housing will deform to agreater extent than the cylinders during cold flow of the material ofthe housing. However, there will be some plastic deformation of thecylinders 360-366.

The force transmitting capability of the suture 52 is enhanced byminimizing stress concentrations in the suture and by transmitting forcefrom the housing 358 to a large area on the body tissue. The bendsformed in the suture 52 around the cylinders 360-366 are free of abruptstress inducing discontinuities. The housing 358 transmits force to thebody tissue located between the opposite sides of the left and rightsections 66 and 68 of the suture 52. Therefore, stress concentrations inboth the body tissue and the suture 52 tend to be minimized. If desired,a knot may be tied between the upper (as viewed in FIG. 20) end portionsof the left and right sections 66 and 68 of the suture 52. Although sucha knot would provide additional assurance that the suture 52 will notwork loose, it is believed that the knot will not be necessary.

One of the ends of the suture could be fixedly connected with thehousing 358. This could be done by forming the suture 52 as one piecewith the housing 358 or by using a fastener. If one end of the suture isfixedly connected with the housing 358, one of the sets of cylinders,for example, the cylinders 360 and 362, could be eliminated.

Embodiment of FIGS. 21-22

In the embodiments of the invention illustrated in FIGS. 9-20, bends areformed in the left and right sections 66 and 68 of the suture 52 bycircular surfaces. In the embodiment of the invention illustrated inFIGS. 21 and 22, the bends are formed in the suture by passages througha rectangular member. Since the embodiment of the invention illustratedin FIGS. 21 and 22 is similar to the embodiment of the inventionillustrated in FIGS. 9-20, similar terminology will be utilized toidentify similar components. It should be understood that one or more ofthe features of the embodiments of the invention illustrated in FIGS.1-20 may be used with the embodiment of the invention illustrated inFIGS. 21-22.

A suture retainer 390 is formed in a single rectangular piece ofbiodegradable material. The suture retainer 390 includes a rectangularbody 392 formed of a suitable biodegradable material. However, therectangular body 392 could be formed of a nonbiodegradable material ifdesired.

A plurality of parallel passages 394, 396 and 398 extend betweenopposite parallel rectangular end surfaces 400 and 402 of the body 392.The left and right sections 66 and 68 of the suture 52 zig-zag throughthe passages 394, 396 and 398 in a side-by-side relationship. Thesections 66 and 68 of the suture 52 zig-zag through the passages 394,396 and 398 to form a series of bends in the suture.

The passages 394, 396 and 398 in the body 392 of the suture retainer 390cooperate to form smooth, continuous bends 406, 408, 410 and 412 (FIG.21) in the sections 66 and 68 of the suture 52. Thus, the left and rightsections 66 and 68 of the suture 52 extend through the straight passage394. Bends 406 and 408 are formed in the portions of the sections 66 and68 of the suture disposed between the passage 394 and the passage 396.Similarly, bends 410 and 412 are formed in the sections 66 and 68 of thesuture 52 disposed between the passages 396 and 398. Of course, if therewere additional passages formed in the rectangular body 392, additionalbends would be formed in the suture 52.

The bends 406-412 in the sections 66 and 68 of the suture 52 are smoothand free of stress inducing discontinuities. By keeping the suture 52free of stress inducing discontinuities, the force which can betransmitted through the suture tends to be maximized. If a knot wassubstituted for the suture retainer 390, stress concentrations would beformed and the force transmitting capability of the suture reduced.

The passage 394 has a main section 418 and a gripping section 420. Thegripping section 420 has a tapered configuration (FIG. 22) and extendssideward from the main section 418. The left and right sections 66 and68 of the suture 52 may be pulled from the main section 418 of thepassage 394 into the gripping section 420 of the passage. As thisoccurs, the side surfaces of the passage 394 grip opposite sides of theleft and right sections 66 and 68 of the suture 52 to hold the left andright sections of the suture against axial movement relative to therectangular body 392 of the suture retainer 390.

The suture retainer 390 is formed of a single piece of biodegradablematerial, such as polycaperlactone. Of course, other suitablebiodegradable or bioerodible materials could be utilized if desired. Itis contemplated that the suture retainer 390 could be formed ofmaterials which do not biodegrade.

After the suture 52 has been inserted into the suture retainer 390, inthe manner illustrated schematically in FIG. 21, the suture retainer ismoved along the suture toward body tissue (not shown). As the sutureretainer 390 is moved along the suture 52, the side-by-side sections 66and 68 of the suture slide in the same direction on surfaces of thesuture retainer 390.

To effect movement of the suture retainer 390 along the suture 52, forceis applied against the body 392, in the manner indicated schematicallyby an arrow 424 in FIG. 21. This causes the body 392 of the sutureretainer 390 to slide along the sections 66 and 68 of the suture 52. Atthis time, the left and right sections 66 and 68 of the suture aretensioned. Therefore, the left and right sections of the suture slidealong surfaces of the passages 394, 396 and 398 as the rectangular body392 of the suture retainer 390 is moved toward the body tissue. As thisoccurs, the bends 406-412 move along the sections 66 and 68 of thesuture 52 toward the body tissue.

When the leading end surface 402 on the rectangular body 392 of thesuture retainer 390 engages the body tissue, the force indicatedschematically by the arrow 424 is increased to a predetermined force. Asthis occurs, a predetermined tensioning force is applied to the left andright sections 66 and 68 of the suture 52. This results in the suture 52being pulled tight to grip the body tissue with a desired force. Therectangular end surface 402 on the body 392 of the suture retainer 390distributes the tension force in the suture 52 over a relatively largearea on the body tissue.

While the retainer body 392 is being pressed against the body tissuewith the predetermined force and the left and right sections 66 and 68of the suture 52 are pulled taut with a predetermined tensioning force,the left and right sections 66 and 68 of the suture may be pulledtowards the right (as viewed in FIGS. 21 and 22). As this occurs, theleft and right sections 66 and 68 of the suture 52 will move from themain section 418 of the passage 394 into the gripping section 420 of thepassage. This results in a frictional grip between the retainer body 392and the suture 52 to hold the suture against movement relative to theretainer body and to maintain the desired tension in the suture.

While the body 392 of the suture retainer 390 is being pressed againstthe body tissue with the predetermined force 424 and while thepredetermined tension is maintained in the left and right sections 66and 68 of the suture 52, the material of the suture retainer 390 isplastically deformed. To plastically deform the material of the sutureretainer 390, force applying members 428 and 430 (FIG. 22) apply apredetermined force against opposite sides of the body 392 of the sutureretainer. This force causes cold flowing of the material of the body 392of the suture retainer.

As the plastic deformation of the body 392 of the suture retainer 390occurs, the passages 394, 396 and 398 are collapsed and the material ofthe body 392 of the suture retainer 390 cold flows around and grips theleft and right sections 66 and 68 of the suture 52. The plasticdeformation of the body 392 of the suture retainer 390 occurs at atemperature below the transition temperature of the material forming thesuture retainer. If desired, the suture retainer 390 could be heated topromote cold flow of the material of the suture retainer.

In the embodiment of the invention illustrated in FIGS. 21 and 22, thegripping section 420 mechanically grips a portion of the suture 52. Ifdesired, the gripping section 420 could be eliminated and the suturemoved into engagement with a projection from the body 392. The upper (asviewed in FIG. 21) portions of the suture 52 could be wrapped around aprojection from the body 392. Alternatively, the upper (as viewed inFIG. 21) portions of the suture could be moved into engagement with oneor more hook-shaped locking notches on the body 392 of the sutureretainer 390.

Embodiments of FIGS. 23-25

In the embodiment of the invention illustrated in FIGS. 21 and 22, theleft and right sections 66 and 68 of the suture 52 extend through thepassages 394, 396 and 398 in a side-by-side relationship. In theembodiments of the invention illustrated in FIGS. 23-25, loops areformed in the left and right sections of the suture around portions ofthe suture retainer. Since the embodiments of the invention illustratedin FIGS. 23-25 is similar to the embodiment of the invention illustratedin FIGS. 21-22, similar terminology will be utilized to identify similarcomponents. It should be understood that one or more features of theembodiments of the invention illustrated in FIGS. 1-22 could be usedwith the embodiments of the invention illustrated in FIGS. 23-25.

A suture retainer 440 (FIG. 23) has a rectangular body 442. A pluralityof straight parallel cylindrical passages 444, 446 and 448 extendbetween flat parallel rectangular end surfaces 450 and 452 of therectangular body 442 of the suture retainer 440. The left and rightsections 66 and 68 of the suture 52 extend through the passages 444, 446and 448 in a zig-zag manner.

The left section 66 of the suture 52 zigzags through the passages 444,446 and 448 in the rectangular body 442 of the suture retainer 440. Whenthe left section 66 of the suture 52 is inserted into the sutureretainer 440, the left section 66 of the suture is first moved downward(as viewed in FIG. 23) through passage 448. A smooth, continuous firstbend 456 is then formed in the left section 66 of the suture 52 and theleft section is moved upward through the passage 446. A smooth,continuous second bend 458 is then formed in the left section 66 of thesuture 52. The left section 66 of the suture 52 is then moved downwardthrough the passage 444.

The right section 68 of the suture 52 is also inserted into the sutureretainer 440 in a zig-zag fashion. Thus, the right section 68 of thesuture 52 is moved downward through the passage 444. A smooth,continuous first bend 462 is formed in the right section 68 of thesuture 52. The right section 68 of the suture 52 is then moved upwardthrough the passage 446. A smooth, continuous second bend 464 is thenformed in the right section 68 of the suture 52. The right section 68 ofthe suture 52 is then moved downward through the passage 448.

In the embodiment of the invention illustrated in FIG. 23, the left andright sections 66 and 68 of the suture 52 are not aligned or in aside-by-side relationship with each other. Thus, the bends 456 and 458in the left section 66 of the suture 52 are offset from the bends 462and 464 in the right section 68 of the suture 52. The bends 456, 458,462, and 464 are free of stress inducing discontinuities which wouldtend to weaken the suture 52.

After the suture 52 has been inserted into the suture retainer 440, inthe manner illustrated schematically in FIG. 23, the left and rightsections 66 and 68 of the suture are tensioned and force is applied tothe rectangular body 442 of the suture retainer 440 to move the sutureretainer along the suture 52 toward the body tissue. As this occurs, theleft and right sections 66 and 68 of the suture 52 slide in oppositedirections along the surfaces of the passages 444, 446 and 448. As thisoccurs, the zig-zag portion of the suture 52 is moved along the suturetoward the body tissue.

When the rectangular leading end surface 452 of the body 442 of thesuture retainer 440 moves into engagement with the body tissue, thesuture retainer is pressed against the body tissue with a predeterminedforce while maintaining a predetermined tension in the left and rightsections 66 and 68 of the suture. The suture retainer 440 is thenplastically deformed to grip the left and right sections 66 and 68 ofthe suture 52. To plastically deform the material of the suture retainer440, force is applied against opposite sides of the suture retainer 440,in the manner indicated by arrows 470 and 472 in FIG. 23.

The force indicated by the arrows 470 and 472 causes cold flow of thematerial of the suture retainer 440. The suture retainer 440 is formedfrom a single piece of biodegradable polymeric material, such aspolycaperlactone. The plastic deformation of the suture retainer 440occurs while the material of the suture is a temperature which is belowthe transition temperature of the material and is at a temperature closeto the temperature of the body tissue. If desired, the suture retainer440 could be heated to a temperature above the temperature of the bodytissue and below the transition temperature of the material of thesuture retainer to promote cold flow of the material of the sutureretainer.

In the embodiment of the invention illustrated in FIG. 24, the sectionsof the suture 52 are wrapped around portions of the suture retainer insmooth, continuous loops. Thus, in the embodiment of the inventionillustrated in FIG. 24, a suture retainer 480 includes a rectangularbody 482 formed of a biodegradable polymeric material. A plurality ofstraight cylindrical passages 484, 486 and 488 extend between and areperpendicular to flat parallel end surfaces 492 and 494 on therectangular body 482 of the suture retainer 480.

The suture 52 includes left and right sections 66 and 68. The left andright sections 66 and 68 are wrapped, in zig-zag fashion, aroundportions 498 and 500 of the rectangular body 482. This results in theformation of left and right loops 502 and 504 in the left and rightsections 66 and 68 of the suture 52. The loops 502 and 504 are free ofstress inducing discontinuities.

When the suture retainer 480 is to be positioned relative to the bodytissue of a human patient, the left and right sections 66 and 68 of thesuture 52 are tensioned with a predetermined force. Force is thenapplied to the rectangular body 482 of the suture retainer to move thesuture retainer downward (as viewed in FIG. 24) along the suture 52. Asthis occurs, the left and right sections 66 and 68 slide along surfacesof the passages 484, 486 and 488. In addition, the loops 502 and 504move downward (as viewed in FIG. 4) along the suture 52.

The leading end surface 494 of the rectangular body 482 is pressedagainst the body tissue with a predetermined force while a predeterminedtension is maintained in the left and right sections 66 and 68 of thesuture 52. The material of the suture retainer 480 is then plasticallydeformed to grip the left and right sections 66 and 68 of the suture 52.When the material of the suture retainer 480 is plastically deformed,the material of the suture retainer is below its transition temperatureand is at a temperature close to the temperature of the body tissue.Therefore, the material of the suture retainer 480 cold flows under theinfluence of force applied against the suture retainer to collapse thepassages 484, 486 and 488 and grip the left and right sections 66 and 68of the suture 52.

The flat rectangular end surfaces of the suture retainer 480 appliesforce over a relatively large surface area on the body tissue. Thisreduces any tendency for the suture 52 to cut or separate the bodytissue. The force which can be transmitted through the suture 52 ismaximized by eliminating sharp bends in the suture. If the sutureretainer 480 was eliminated and the suture was secured with a knot, thesuture would be weakened by stress concentrations formed at sharp bendsin the knot.

In the embodiment of the invention illustrated in FIG. 25, a sutureretainer 510 includes a rectangular body 512 formed of a biodegradablepolymeric material. A plurality of straight parallel cylindricalpassages 514, 516, 518, and 520 extend between flat rectangular endsurfaces 522 and 524 of the body 512.

The suture 52 includes left and right sections 66 and 68. Separate leftand right loops 530 and 532 (FIG. 25) are formed in the sections 66 and68 of the suture 52. Thus, the left loop 530 in the left section 66 ofthe suture 52 extends through the passages 518 and 520 in therectangular body 512 of the suture retainer 510. Similarly, the rightloop 532 extends through the passages 514 and 516 in the rectangularbody 512 of the suture retainer 510.

When the suture retainer 510 is to be positioned relative to bodytissue, the left and right sections 66 and 68 of the suture 52 aretensioned. Force is then applied to the suture retainer 510 to move thesuture retainer downward (as viewed in FIG. 25) along the suture 52 intoengagement with the body tissue. After the lower end surface 524 of therectangular body 512 of the suture retainer 510 has been pressed againstthe body tissue with a predetermined force, the biodegradable polymericmaterial of the suture retainer 510 is plastically deformed by applyingforce against the suture retainer and cold flowing the material of thesuture retainer. Cold flow of the material of the body 512 collapses thepassages 514-520. The material of the body 512 then firmly grips thesuture 52.

After plastic deformation of the material of the body 512, the sutureretainer 510 at a temperature below the transition temperature of thematerial, a knot may be tied between the upper portions of the suture.This knot would be pressed tightly against the upper end surface 522 ofthe rectangular body 512 of the suture retainer 510. This know would bedisposed at a location between the locations of the passages 516 and 518before plastic deformation of the body 512 of the suture retainer 510.It is believed that such a knot may not be necessary.

In the embodiment of the invention illustrated in FIGS. 24 and 25, thepassages through the rectangular bodies of the suture retainer areshorter than the passages through the rectangular body of the sutureretainer illustrated in FIG. 23. However, it should be understood thatthe passages through the rectangular bodies of the suture retainersillustrated in FIGS. 24 and 25 could have a longer length if desired.

In the embodiments of the invention illustrated in FIGS. 23-25, thesuture 52 is separate from the suture retainers 440, 480 and 510.However, one end of the suture 52 could be connected with any one of hesuture retainers 440, 480 and 510. If this was done only one of thesections 66 or 68 would be zigzagged through passages in a sutureretainer. For example, an end of the left section 66 of the suture 52may be fixedly connected with one of the suture retainers 440, 480 or510. Only the right section 68 of the suture 52 would have to beinserted through the passages in the one suture retainer 440, 480 or510. The end of the suture 52 could be fixedly connected with a sutureretainer 440, 480 or 5110 by a suitable fastener or by forming thesuture as one piece with the suture retainer.

Embodiment of the Invention Illustrated in FIGS. 26, 27 and 28

In the embodiment of the invention illustrated in FIGS. 21-25, thesuture retainer is formed form a single piece of biodegradable polymericmaterial. In the embodiment of the invention illustrated in FIGS. 26-28,the suture retainer is formed from a plurality of pieces ofbiodegradable polymeric material. Since the embodiment of the inventionillustrated in FIGS. 26-28 is similar to the embodiment of the inventionillustrated in FIGS. 21-25, similar terminology will be utilized toidentify similar components. It should be understood that one or more ofthe features of the embodiments of the invention illustrated in FIGS.1-25 could be used with the embodiment of the invention illustrated inFIGS. 26-28.

A suture retainer 540 (FIG. 26) includes a base 542 (FIGS. 26 and 27)and a sleeve or cap 544 (FIGS. 26 and 28). The base 542 has a circularflange 548 which extends radially outward from an upstanding central orpost portion 550 (FIGS. 26 and 27). The post portion 550 has a generallycylindrical configuration and is disposed in a coaxial relationship withthe circular flange 548. The flange 548 and post portion 550 areintegrally formed from one piece of a biodegradable material, such aspolycaperlactone. However, the base 542 and/or the cap 544 could beformed of a material which is not biodegradable.

A pair of passages 554 and 556 are provided in the post portion 550. Thepassage 554 includes a radially inward and downward sloping entranceportion 558 and a main portion 560. The main portion 560 extendsparallel to the longitudinal central axis of the post portion 550. Theentrance portion 558 of the passage 554 extends inwardly from acylindrical outer side surface 562 of the post portion 550. The mainportion 560 of the passage 554 extends perpendicular to a flat circularbottom side surface 564 of the flange 548.

The passage 556 has the same configuration as the passage 554. Thepassage 556 is disposed diametrically opposite to the passage 554. Thepassages 554 and 556 have a nonlinear configuration and form bends in heleft and right sections 66 and 68 of the suture 52. The passages 554 and556 are circumscribed by an annular recess 568 which extends around thelower end of the post portion 550 adjacent to the flange 548.

The upper end of the post portion 550 has a flat circular side surface570 (FIG. 27). The flat side surface 570 on the post portion 550 extendsparallel to and is coaxial with the flat bottom side surface 564 (FIG.26) on the flange 548. The annular recess 568 is coaxial with the flange548. The base portion 542 is formed of a biodegradable material, such aspolycaperlactone. Other polymers which are biodegradable or bioerodiblemay be used. It is also contemplated that the base portion 542 could beformed of a polymer which does not biodegrade, such as an acetyl resin.

In addition to the base portion 542, the suture retainer 540 includesthe one piece, cylindrical cap or sleeve 544 (FIG. 28). The cap 544 hasa cylindrical outer side surface 574. A circular end surface 576 extendsradially inwardly from the side surface 547. The cap 544 has acylindrical cavity 578 (FIG. 26) which is disposed in a coaxialrelationship with the cylindrical outer side surface 574 and end surface576.

A pair of cylindrical passages 582 and 584 extend between the cavity 578and the circular end surface 576 of the cap 544 (FIG. 26). The cavity578 has a cylindrical side surface 588 which is disposed in a coaxialrelationship with the outer side surface 574 on the cap 544. Inaddition, the cavity 578 has a circular end surface 590 which extendsparallel to and is coaxial with the outer end surface 576 on the cap 544(FIG. 26). An annular rib 594 (FIG. 26) projects radially inward fromthe cylindrical inner side surface 588 of the cavity 578. The cap 544 isintegrally formed as one piece of a suitable biodegradable polymericmaterial, such as polycaperlactone. However, the cap 544 may be formedof a material which is not biodegradable.

When the suture 52 is to be connected with body tissue 54 (FIG. 26), oneof the sections of the suture, for example, the right section 68, isthreaded through the passage 582 into the cavity 578 in the cap 544. Atthis time, the suture 52 extends away from the cap 544 so that the leftsection 66 of the suture is disposed at a remote location. The rightsection 68 of the suture is then threaded through the passage 554 in thebase portion 542. The right section 68 of the suture 52 is then threadedthrough a passage 598 in the body tissue 54.

In addition, the right section 68 of the suture 52 is threaded through apassage 600 in a force distribution member or button 602 which engages alower side of the body tissue 54. The suture 52 is then threaded througha second passage 604 in the button 602 and a passage 606 in the bodytissue 54. The button 602 distributes tension forces in the suture 52over a relatively large area on the lower (as viewed in FIG. 26) side108 of the body tissue. However, the button 602 could be omitted ifdesired.

The right section 68 of the suture is then threaded upward (as viewed inFIG. 26) through the passage 556 in the base portion 542 and into thecavity 578 in the cap 544. The right section 68 of the suture 52 isthreaded out of the cavity 568 through the passage 584. As this occurs,the left section 66 of the suture 52 is pulled into the cap 544 and baseportion 542.

Once the suture 52 has been threaded through the base portion 542 andcap 544 in the manner previously explained, the sections 66 and 68 ofthe suture are tensioned and the base portion 542 is slid along thesuture 52. As this occurs, the bends formed in the left and rightsections 66 and 68 of the suture 52 by the passages 554 and 556 in thebase portion 542 are moved along the suture toward the body tissue 54.The bottom side surface 564 of the base portion 542 is then pressedagainst an upper side surface 98 of the body tissue 54 in the mannerillustrated in FIG. 26.

The flat circular bottom side surface 564 of the flange 548 transmitsforce from the suture 52 to a relatively large area on the surface 98 ofthe body tissue 54. At this time, the tension in a connector portion 610of the suture 52 will pull the force distribution member or button 602firmly upward against a lower side surface 108 of the body tissue 54.This results in the body tissue 54 being clamped between the relativelylarge bottom surface area on the flange 548 and the button 602.

While the tension is maintained in the left and right sections 66 and 68of the suture 52, the cap 544 is slid downward along the suture 52 intoengagement with the base portion 542. Further downward movement of thesleeve or cap 544 resiliently deflects the rib 594 radially outward.Continued downward movement (as viewed in FIG. 26) of the sleeve or cap544 moves the rib 594 along the outer side surface 562 of the postportion 542 into alignment with the recess 568. As this occurs, the rib594 snaps into the recess 568.

Once the rib 594 is snapped into the recess 568, the left and rightsections of the suture 52 are firmly gripped between the cylindricalinner side surface 588 of the cavity 578 in the cap 544 and thecylindrical outer side surface 562 of the post portion 550. In addition,the left and right sections 66 and 68 of the suture 52 are grippedbetween the circular end surface 590 of the cavity 578 and the circularend surface 570 of the post portion 550. The cap 544 and post portion550 cooperate to form bends in the left and right sections 66 and 68 ofthe suture.

Under certain circumstances, it is believed that the mechanical grippingaction provided between the cap 544 and base portion 542 of the sutureretainer 540 may be sufficient to hold the suture 52 against movementrelative to the body tissue. However, it is believed that it will bepreferred to enhance the grip of the suture retainer 540 on the suture52 by plastically deforming the material of the suture retainer. Theplastic deformation of the suture retainer 540 occurs with the sutureretainer at a temperature which is below the transition temperature ofthe biodegradable polymeric material forming the base portion 542 andcap 544 of the suture retainer.

Plastic deformation of the base portion 542 and cap portion 544 of thesuture retainer 540 is accomplished by applying force against thecylindrical outer side surface 574 of the cap 544 in the same manner asillustrated schematically in FIG. 12. The force applied against thecylindrical outer side surface 574 (FIG. 26) of the cap 544 causes thematerial of the cap to cold flow and press against the left and rightsections 66 and 68 of the suture 52. As this occurs, the passages 554and 556 in the base portion 542 collapse. Due to the bends provided inthe left and right sections 66 and 68 of the suture 52 in passingthrough the passages 554 and 556, and around the outside of the postportion 550 of the base portion 542, there is an extremely securegripping action of the suture 52 upon plastic deformation of material ofthe cap 544 and base portion 542.

The force applied against the outer side surface 574 of the cap 544 issufficient to cause cold flow of the material of the cap 544 and postportion 550. Cold flow of the material of the cap 544 firmly clamps thesections 66 and 68 of the suture 52 between the cap and post portion550. Cold flow of the material of the post portion 550 collapses thepassages 554 and 556. This results in a cold bonding of the material ofthe post portion 550 with the suture 52. The suture 52 is then securelygripped by the post portion 554.

It is preferred to form the base portion 542 and the cap 544 of thesuture retainer 540 of the same biodegradable polymeric material.However, the base portion 542 could be formed of a biodegradablematerial which is somewhat harder than the biodegradable materialforming the cap 544. This would facilitate plastic deformation of thecap 544 under the influence of force applied against the outer sidesurface 574 of the cap. If desired, the base portion 542 and/or cap 544could be formed of a material which does not biodegrade.

After the suture retainer 540 has been plastically deformed by coldflowing the material of the suture retainer, the suture 52 may beknotted. Thus, a knot may be tied to interconnect the left and rightsections 66 and 68 of the suture 52 in a known manner. During the tyingof this knot, the suture 52 is pulled taut against the end surfaces 576on the cap 544. The knot will be disposed between the passages 582 and584 in the cap 544. The knot will not reduce the overall forcetransmitting capability of the suture 52 since the suture retainer 540will be disposed between the knot and the body tissue 54. Although sucha knot may be provided to be certain that the suture 52 does not workloose under the influence of varying loads, it is believed that thesuture retainer 540 will be very capable of holding the suture 52without the additional protection provided by the knot.

Embodiment of FIG. 29

In the embodiment of the invention illustrated in FIGS. 13-16, thesuture 52 is wrapped around a conical body 242 which is moved into asleeve 284 of a suture retainer 244. In the embodiment of the inventionillustrated in FIG. 29, the suture extends through passages formed in aconical body and a sleeve. Since the embodiment of the inventionillustrated in FIG. 29 is similar to the embodiment of the inventionillustrated in FIGS. 13-16, similar terminology will be utilized toidentify similar components. It should be understood that one or more ofthe features of the embodiments of the invention illustrated in FIGS.1-28 could be used with the embodiment of the invention illustrated inFIG. 29.

A suture retainer 622 includes a conical body 624 and a cylindricalsleeve or base 626. The conical body 624 has an outer side surface 628which is formed as a portion of a right circular cone. The outer sidesurface 628 of the conical body 624 extends between flat parallelcircular end surfaces 630 and 632. The end surfaces 630 and 632 aredisposed in a coaxial relationship with each other and with the outerside surface 628 of the conical body 624. The end surface 632 of theconical body 624 has a diameter which is smaller than the diameter ofthe end surface 630 of the conical body.

A pair of cylindrical passages 636 and 638 are disposed in the conicalbody 624. The passages 636 and 638 have straight central axes which areskewed at an acute angle to the central axis of the conical body 624. Ifdesired, the passages 636 and 638 could have nonlinear central axes topromote the forming of bends in the suture 52. For example, the passages636 and 638 could have a helical configuration. The conical body 624 isformed from a single piece of a biodegradable polymeric material, suchas polycaperlactone.

The cylindrical sleeve 626 has a cylindrical outer side surface 642. Theside surface 642 extends between a flat annular end surface 644 and acircular end surface 646. The end surfaces 644 and 646 extend parallelto each other and are disposed in a coaxial relationship.

A recess 650 is formed in the cylindrical sleeve 626. The recess 650 isof the same size and configuration as the conical body 624. The recess650 has a side wall 652 which is formed as a portion of a cone. Inaddition, the recess 650 has a circular end surface 654 which extendsparallel to the outer end surface 646 on the sleeve 626. The side wall652 of the recess 650 has the same angle of taper as the outer sidesurface 628 of the conical body 624. However, if desired, the taper inthe side wall 652 of the recess 650 could be slightly less than thetaper in the outer side surface 628 of the conical body 624 to promote awedging action between the conical body and the sleeve 626.

A pair of parallel cylindrical passages 660 and 662 extend between andare perpendicular to the end wall 654 of the recess 650 and the endsurface 646 on the sleeve 626. The passages 660 and 662 have a linearconfiguration. However, the passages 660 and 662 could have a nonlinearconfiguration if desired.

When the suture retainer 622 is to be positioned relative to bodytissue, the left section 66 of the suture 52 is inserted through thepassage 660 in the sleeve 626. The left section 66 of the suture 52 isthen inserted through the passage 636 in the conical body 624.Similarly, the right section 68 of the suture 52 is inserted through thepassage 662 in the sleeve 626 and the passage 638 in the conical body624.

The left and right sections 66 and 68 of the suture 52 are thentensioned and the sleeve 626 is moved along the suture 52 intoengagement with the body tissue. When the end surface 646 of the sleevehas engaged the body tissue, the force applied against the sleeve andtension in the sections 66 and 68 of the suture 52 are increased. Whilea predetermined force is applied against the sleeve 626, the conicalbody 624 is moved along the left and right sections 66 and 68 of thesuture 52 into the recess 650 in the sleeve. As this occurs, the leftand right sections 66 and 68 of the suture are clamped between the outerside surface 628 of the conical body 624 and the conical side wall 652of the recess 650.

To enhance the gripping action between the conical body 624 and thesleeve 626, force is applied against the cylindrical outer side surface642 of the sleeve in the same manner as indicated schematically in FIG.12. This force causes plastic deformation of the material of the sleeve626 to firmly grip the conical body 624 and the left and right sections66 and 68 of the suture 52. The force applied against the outer sidesurface 642 of the sleeve 626 causes a cold flowing of the material ofthe sleeve 626. The cold flowing of the material of the sleeve 626 willcollapse the passages 660 and 662 to firmly grip the portion of the leftand right sections 66 and 68 of the suture 52 extending through thepassages.

In addition, the force applied against the sleeve 626 will be sufficientto cause plastic deformation, that is, cold flowing, of the material ofthe conical body 624 to collapse the passages 636 and 638. This resultsin the portions of the left and right sections 66 and 68 of the suture52 disposed in the passages 636 and 638 being firmly gripped by materialof the conical body 624.

It is contemplated that one end of the suture 52 could be fixedlyconnected with the suture retainer 622. Thus, one end of the suture 52could be fixedly connected with the conical body 624. Alternatively, oneend of the suture 52 could be fixedly connected with the sleeve 626.

It is also contemplated that a knot could be tied between the left andright sections 66 and 68 of the suture 52 at a location above (as viewedin FIG. 92) the suture retainer. The knot would be tied adjacent to theend surface 650 on the conical body 624. The knot would be tiedimmediately after plastically deforming the material of the sutureretainer. It should be understood that the suture retainer 622 should bemore than adequate to hold the suture 52 and the knot may be omitted.

The use of the suture retainer 622, rather than forming a knot tointerconnect the two sections 66 and 68 of the suture 52, increases theforce transmitting capability of the suture 52. This is because thestress concentrations induced by the forming of a knot are avoided.

In addition, the use of the suture retainer 62, rather than forming aknot to interconnect the two sections 66 and 68 of the suture 52,reduces stress concentrations in the body tissue. The flat end surface646 distributes tension forces in the suture 52 over a relatively largesurface area on the body tissue. This minimizes stress concentrations inthe body tissue and minimizes any tendency for the body tissue to be cutor separated by the force applied against the body tissue.

Embodiment of FIGS. 30 and 31

In the embodiment of the invention illustrated in FIG. 29, the left andright sections 66 and 68 of the suture 52 are inserted into passagesformed in the conical body 624. In the embodiment of the inventionillustrated in FIGS. 30 and 31, the conical body 34 has a hinge sectionwhich is pivotal to open the conical body and facilitate insertion ofthe left and right sections of the suture. Since the embodiment of theinvention illustrated in FIGS. 30 and 31 is similar to the embodiment ofthe invention illustrated in FIG. 29, similar terminology will beutilized to identify similar components. It should be understood thatone or more of the features of the embodiments of the inventionillustrated in FIGS. 1-92 could be used with the embodiment of theinvention illustrated in FIGS. 30 and 31.

A suture retainer 670 (FIG. 30) includes a conical body 672 and a sleeve674. The conical body 672 is formed as two sections 676 and 678 (FIG.31). The sections 676 and 678 of the conical body are pivotallyinterconnected at a hinge 680. The hinge 680 is integrally formed as onepiece with the sections 676 and 678 of the conical body 672. The hinge680 enables the left and right sections 66 and 68 (FIG. 30) of thesuture 52 to be inserted through an opening 684. The opening 684 extendsbetween axially opposite ends of the conical body 672.

The sleeve 674 includes a circular flange 688 which extends radiallyoutward from a cylindrical outer side surface 690 of the sleeve 674. Aconical recess 692 has a relatively large open end in an upper annularend surface 694 of the sleeve 674 and a relatively small open end in aflat annular end surface 696 disposed on the bottom of the flange 688.

The left and right sections 66 and 68 of the suture are inserted throughthe open ended conical recess 692 in the sleeve 674. The left and rightsections 66 and 68 of the suture 52 are then inserted through theopening 684 (FIG. 31) into the conical body 672.

While tension is maintained in the left and right sections 66 and 68 ofthe suture 52, the sleeve 674 is moved along the suture until theleading end surface 696 on the bottom of the flange 688 engages the bodytissue. The sleeve 674 is then pressed against the body tissue with apredetermined force while a predetermined tension is maintained in theleft and right sections 66 and 68 of the suture 52. The conical body 672is then moved along the left and right sections 66 and 68 of the suture52 into the open ended recess 692 in the sleeve 674.

Force is then applied against the outer side surface 690 of the sleeve674 to plastically deform the sleeve. As this occurs, the material ofthe sleeve 674 cold flows radially inward and applies force against theconical body 672. This force is sufficient to cause cold flowing of thematerial of the conical body and gripping of the left and right sections66 and 68 of the suture 52 with the material of the conical body 672.

The conical body 672 and sleeve 674 are formed of a biodegradablematerial. However, the conical body 672 and/or sleeve 674 could beformed of a different material if desired.

Embodiment of FIGS. 32 and 33

In the embodiment of the invention illustrated in FIGS. 29, 30 and 31,two-piece suture retainers are utilized to grip the left and rightsections of the suture 52. In the embodiment of the inventionillustrated in FIGS. 32 and 33, a one-piece tubular suture retainer isutilized to grip the left and right sections of the suture. Since theembodiment of the invention illustrated in FIGS. 32 and 33 is similar tothe embodiment of the invention illustrated in FIGS. 29-31, similarterminology will be utilized to identify similar components. It shouldbe understood that one or more of the features of the embodiments of theinvention illustrated in FIGS. 1-31 could be used with the embodiment ofthe invention illustrated in FIG. 32.

In the embodiment of the invention illustrated in FIG. 32, a sutureretainer 700 is formed from a single piece of a biodegradable polymericmaterial, such as polycaperlactone. The suture retainer 700 includes anannular flange or base 702 and an upright tubular cylindrical mainsection 704. The tubular cylindrical main section 704 is disposed in acoaxial relationship with the base 702. A straight cylindrical passage706 extends through the tubular main section 704 and base 702 of thesuture retainer 700. If desired, the passage 706 could have a nonlinearconfiguration.

Left and right sections 66 and 68 of the suture 52 are inserted throughthe passage 706 in the suture retainer 700. While a predeterminedtension is maintained in the left and right sections 66 and 68 of thesuture 52, a predetermined force, indicated schematically by the arrows708 in FIG. 32, is applied to the main section 704 of the sutureretainer. The force 708 is distributed over a relatively large surfacearea on the body tissue 54 by the base 702.

The suture retainer 700 is then plastically deformed to grip the leftand right sections 66 and 68 of the suture 52. To plastically deform thesuture retainer 700, force application members 712 and 714 are pressedagainst opposite sides of the main section 704 of the suture retainer700 with a predetermined force, indicated schematically by the arrows716 in FIG. 32. When the force 716 is applied to the suture retainer700, the suture retainer is at a temperature below the transitiontemperature of the material forming the suture retainer. Therefore, theforce 716 is effective to cause cold flow of the material of the sutureretainer 700.

The force applied against the suture retainer 700 by the force applyingmembers 712 and 714 is measured by a transducer or load cell 720. Themagnitude of the force 716 is transmitted from the load cell 720 to adisplay unit 722. When a predetermined minimum force 716 has beenapplied to the suture retainer 700 for a predetermined minimum period oftime by the force applying members 712 and 714, the display unit 722activates an indicator 724.

The force applying members 712 and 714 are configured to form aplurality of bends 728 and 730 in the tubular main section 704 of thesuture retainer 700 (FIG. 33). Thus, the force applying members 712 and714 deform the main section 704 of the suture retainer 700 from astraight cylindrical configuration (FIG. 32) to a nonlinearconfiguration (FIG. 33). The bends 728 and 730, in combination with thecold plastic deformation of the material of the suture retainer 700,result in the suture retainer 700 having a firm grip on the left andright sections 66 and 68 of the suture 52. It should be understood thatthe force application members 712 and 714 could be configured to form agreater number of bends in the main section 704 of the suture retainer.

In the illustrated embodiment of the suture retainer 700, a singlepassage 706 (FIG. 32) extends through the suture retainer. If desired, aplurality of passages could be provided in the suture retainer 700. Ifthis was done, the left section 66 of the suture would be insertedthrough one of the passages and the right section 68 would be insertedthrough another passage.

The bends 728 and 730 (FIG. 33) in the suture retainer 700 form smooth,continuous bends in the suture 52. This avoids the formation of stressconcentrations in the suture 52. If a knot had been utilized in place ofthe suture retainer 700 to interconnect the sections 66 and 68 of hesuture 52, stress concentrations would have been formed in the sutureand the overall force transmitting capability of the suture would havebeen impaired.

The annular base 702 projects radially outward from the cylindrical mainsection. Sine the tension force transmitted to the suture retainer 700by the suture 52 is transmitted to the body tissue 54 by the base 702,the suture tension force is transmitted to a relatively large surfacearea on the body tissue. This minimizes the possibility of the suture 52and suture retainer 700 being pulled downward (as viewed in FIG. 33)into the body tissue 54 by the tension force in the suture. In addition,the large base 702 minimizes the possibility of damage to the bodytissue 54.

If desired, a knot could be tied between the upper end portions of thesections 66 and 68 of the suture. This knot would be disposed above andwould press against an upper (as viewed in FIG. 33) end of the sutureretainer. Although stress concentrations would be formed in the suture52 at the knot, the knot would not impair the force transmittingcapability of the portion of the suture engaging the body tissue 54.This is because the suture retainer 700 would be disposed between thebody tissue 54 and the knot.

Embodiment of FIG. 34

In the embodiment of the invention illustrated in FIG. 34, the sutureretainer has a tubular configuration. Since the embodiment of theinvention illustrated in FIG. 34 is similar to the embodiments of theinvention illustrated in FIGS. 1-33, similar terminology will beutilized to identify similar components. It should be understood thatone or more of the features of the embodiments of the inventionillustrated in FIGS. 1-33 could be used with the embodiment of theinvention illustrated in FIG. 34.

A suture 52 (FIG. 34) has left and right sections 66 and 68 which extendthrough a tubular cylindrical suture retainer 740 into body tissue 54.An apparatus 741 for pressing the suture retainer 740 against the bodytissue 54 includes a tubular cylindrical plunger 742 having acylindrical central passage 744 through which the left and rightsections 66 and 68 of the suture 54 extends. The plunger 742 is enclosedin a tubular cylindrical housing 746.

The plunger 742 is pressed downward, relative to the housing 746 againstthe suture retainer 740 with a predetermined force, indicated by arrows748 in FIG. 34. An annular transducer or load cell 750 provides anoutput indicative of the magnitude of the force 748 with which thesuture retainer 740 is pressed against the body tissue 54 by the plunger742.

While the left and right sections 66 and 68 of the suture 54 are beingtensioned with a predetermined force and while the plunger 742 is beingpressed against the suture retainer 740 with a predetermined force, thesuture retainer 740 is plastically deformed. To plastically deform thesuture retainer 740, a plurality of force applying or clamp members 754and 756 are pressed against the suture retainer with a predeterminedminimum force, indicated schematically by arrows 760 in FIG. 34. Theforce application members 754 and 756 may have an arcuate configurationto conform to the cylindrical configuration of the suture retainer 740or may have a flat configuration. The force applied against the sutureretainer 740 by the force 760 applying members 754 and 756 is sufficientto cause plastic deformation of the material of the suture retainer.

The force 760 is applied against the suture retainer while the sutureretainer is at a temperature which is below the transition temperatureof the biodegradable polymer which forms the suture retainer. Thus, thesuture retainer is at approximately the same temperature as the bodytissue 54 when the force 760 is applied against the suture retainer. Theforce 760 causes the material of the suture retainer to cold flow andgrip the left and right sections 66 and 68 of the suture 54 in themanner previously explained.

Although the apparatus 741 has been illustrated in FIG. 34 inassociation with the suture retainer 740, it is contemplated that theapparatus 741 could be used with any one of the suture retainers ofFIGS. 1-33. Although the force applying members 754 and 756 have anarcuate configuration to grip the arcuate outer side surface of thesuture retainer 740. It is contemplated that the force applying memberscould have a different configuration to grip a suture retainer having anoncylindrical configuration.

Embodiment of FIG. 35

In the embodiment of the invention illustrated in FIG. 35, an apparatussimilar to the apparatus illustrated in FIG. 34 is utilized to install asuture retainer having the same construction as the suture retainer ofFIGS. 13-16. Since the embodiment of the invention illustrated in FIG.35 is similar to the embodiment of the invention illustrated in FIG. 34,similar terminology will be utilized to identify similar components.

An apparatus or tool 770 (FIG. 35) is utilized to position a sutureretainer 772 relative to body tissue 54. The apparatus 770 includes atubular housing or base 774 through which a cylindrical plunger 776extends. A force application member 778 extends from the plunger 776 andis engageable with an upper or trailing end surface 780 of the sutureretainer 772. A biasing spring 782 urges the force application member778 to the extended position illustrated in FIG. 35.

Upon application of a predetermined force to the trailing end surface780 of the suture retainer 772 by the force application member 778, anindicator connected with a shaft 786 indicates to an operator of theapparatus 770 that a desired force has been applied against the sutureretainer 772. The indicator may be either a direct reading of theposition of the shaft 786 relative to the plunger 776 or an output froma transducer, such as a load cell.

The apparatus 770 includes a gripper assembly 790 which is operable togrip and to deform the suture retainer 772. The gripper assembly 790includes a left force application member 792 and a right forceapplication member 794. The force application members 792 and 794 engageopposite sides of the suture retainer 772. The force application members792 and 794 are configured to correspond to the shape of an outer sidesurface of the suture retainer 772.

An actuator member 798 is connected with the left force applicationmember 792. A second actuator member 800 is connected with the rightforce application member 794. The actuator members 798 and 800 arepivotally mounted on the housing 774 at a pivot connection indicatedschematically at 802 in FIG. 35.

Downward force is manually applied to an upper input end portion 806 ofthe plunger 776 while a predetermined tension is maintained in the leftand right sections 66 and 68 of the suture 52. The downward (as viewedin FIG. 35) force applied against the plunger 776 is transmitted throughthe spring 782 to the force application member 778. The forceapplication member 778 applies force to the trailing end surface 780 ofthe suture retainer 772 to press a leading end surface 810 on the sutureretainer 772 against the side surface 98 of the body tissue 54.

An adjustable stop member 812 is connected with the housing 774. Thestop member 812 is adjustable to limit the extent of downward movementof the input end portion 806 of the plunger 776 relative to the housing774. This enables the stop member 812 to limit the amount of forcetransmitted through the spring 782 to the suture retainer 772 to apredetermined force.

Manual force is applied against upper (as viewed in FIG. 35) endportions 816 and 818 of the actuator members 798 and 800. During theapplication of the manual force to the upper end portions 816 and 818 ofthe actuator members 798 and 880, the predetermined tension ismaintained in the left and right sections 66 and 68 of the suture 52. Inaddition, the predetermined downward force is transmitted from theplunger 776 through the spring 782 and force application member 778 tothe suture retainer 772. The manual force applied to the end portions816 and 818 of the actuator members 798 and 800 is transmitted to theforce application members 792 and 794. The force application members 792and 794 are pressed against the suture retainer 792 with sufficientforce too plastically deform the suture retainer by cold flowing thematerial of the suture retainer.

Although the suture retainer 772 may have any one of the constructionsillustrated in FIGS. 1-34, the suture retainer 772 has the sameconstruction as the suture retainer 244 of FIG. 13. Thus, the sutureretainer 772 includes a conical body 822 and a cylindrical sleeve 824.The suture 52 has a left section 66 which is wrapped for a plurality ofturns around the conical body 822 and is disposed in a helical groove830 formed in the conical body 822. Similarly, a right section 68 of thesuture 52 is wrapped for a plurality of turns around the conical body822 and is disposed in a helical groove 832 formed in the conical body822.

When the suture retainer 772 is to be positioned relative to the bodytissue 54, the suture 52 is inserted through the sleeve 824. The leftsection 66 of the suture is then positioned in the helical groove 830 inthe conical body 822 of the suture retainer 772. The right section 68 ofthe suture 52 is positioned in the helical groove 832 in the conicalbody 822 of the suture retainer 772.

The apparatus or tool 770 is then operated to hold the suture retainer772 in the manner illustrated schematically in FIG. 35. Thus, the forceapplication member 778 is positioned in abutting engagement with thetrailing end surface 780 of the suture retainer 772. At the same time,the left and right force application members 792 and 794 grip the sleeve824 of the suture retainer 772. This results in the conical body 822 ofthe suture retainer 772 being telescopically pressed into the sleeve 824while the sleeve is held by the force application members 792 and 794.

While the predetermined tension is maintained in the left and rightsections 66 and 68 of the suture 52, the tool 770 and the sutureretainer 772 are moved along the suture 52 toward the body tissue 54.The tool 770 is moved along a path which extends parallel to the tautportions of the left and right sections 66 and 68 of the suture 52 whichextend upward (as viewed in FIG. 35) from the suture retainer 772. Asthe suture retainer 772 is moved along the suture 52 toward the bodytissue 54, the left and right sections 66 and 68 of the suture slidealong the grooves 830 and 832. The grooves 830 and 832 are effective tomaintain the helical turns or loops in the left and right sections 66and 68 of the suture 52 as the suture retainer 772 moves along thesuture 52 toward the body tissue 54.

The force required to slide the suture retainer 772 along the suture 52is transmitted from the tool 700 to the suture retainer. Thus, force istransmitted from the force application member 778 to the trailing endsurface 780 of the conical body 822. At the same time, a clamping forceis transmitted from the force application members 792 and 794 to thesleeve 824. The sleeve 824 is securely held by the force applicationmembers 792 and 794 while the conical body 822 is pressed axiallyagainst the sleeve by the force application member 778. During movementof the suture retainer 772 along the suture 52, the force appliedagainst the suture retainer by the tool 700 is ineffective to causesignificant deformation of the suture retainer.

At this time, the tool 770 extends along the portions of the left andright sections 66 and 68 of the suture 52 extending upward (as viewed inFIG. 35) from the suture retainer 772. Since the tool 770 extends fromthe suture retainer 772 in the same direction as the left and rightsections 66 and 68 of the suture 52, the tool can be used to positionthe suture retainer relative to body tissue 54 in very restricted spacecommonly present in operating environments.

When the leading end surface 810 on the suture retainer 772 engages theupper (as viewed in FIG. 35) side surface 98 of the body tissue 54 (FIG.35), the force applied against the actuator members 798 and 800 isreduced. Manual force is then applied against the input end portion 806of the plunger 776 to move the plunger downward and compress the spring782. The stop member 812 is engaged by the input end portion 806 of theplunger 776 when a predetermined force is being transmitted through thespring 782 and force application member 778 to the suture retainer 772.

This results in the predetermined downward force being transmitted fromthe force application member 778 to the suture retainer 772 to press theconical body against the sleeve 824. The predetermined downward force isthen transmitted from the sleeve 824 and conical body 822 to the bodytissue 54. While the suture retainer 772 is being pressed against thebody tissue with the predetermined downward force, a predeterminedtension force is maintained in the left and right sections 66 and 68 ofthe suture 52.

In the schematic illustration of FIG. 35, there is space between theconical body 822 and the sleeve 824. In addition, there is space betweenthe sleeve 824 and the force application members 792 and 794. It shouldbe understood that the conical outer side surface of the body 822 ispressed firmly against the correspondingly shaped conical inner sidesurface of the sleeve 824. It should also be understood hat the forceapplication members 792 and 794 are pressed against the cylindricalouter side surface of the sleeve 824. At this time, the left and rightsections 66 and 68 of the suture are tensioned.

While the predetermined force is being applied against the trailing endsurface 780 of the suture retainer 772 by the force application member778, manual force is applied against the upper end portions 816 and 818of the actuator members 798 and 800 to effect plastic deformation of thesuture retainer 772. Thus, the left and right force applying members 792and 794 are pressed against the cylindrical sleeve 824 with sufficientforce to plastically deform both the cylindrical sleeve and the conicalbody 822 of the suture retainer 772. At this time, the suture retainer772 is at approximately the same temperature as the body tissue 54 andis at a temperature which is below the transition temperature of thebiodegradable polymeric material forming the suture retainer. Therefore,cold flowing the material of the suture retainer occurs under theinfluence of the force applied against the suture retainer 772 by theleft and right force applying members 792 and 794.

The cold flowing of the material of the suture retainer 772 under theinfluence of the force applied to the suture retainer by the forceapplication members 792 and 794 results in the suture 52 being firmlygripped in the manner set forth in association with the suture retainer244 of the embodiment of FIGS. 13-16. The application of force to theactuator members 798 and 800 is then interrupted. The application offorce to the input end portion 806 of the plunger 776 is alsointerrupted. The apparatus 770 is then moved upward (as viewed in FIG.35) away from the suture retainer.

Although the apparatus 770 has been disclosed herein in association withthe suture retainer 772, it is contemplated that the apparatus could beutilized to install suture retainers having a different construction. Ifthe apparatus 770 is used to install a suture retainer having an outerside surface with a configuration which is different than theconfiguration of outer side surface of the suture retainer 772, theconfiguration of the force application members 792 and 794 would bemodified to correspond to the configuration of the suture retainer to beinstalled. For example, if the suture retainer had a flat outer sidesurface, the force application members 792 and 794 would be modified tohave flat surfaces to engage the suture retainer. If the suture retainerhad the spherical outer side surface of the suture retainer 50 (FIG. 2),the force application members 792 and 794 would have configurationscorresponding to the configuration of portions of a sphere.

Embodiment of the Invention Illustrated in FIG. 36

In the embodiment of the invention illustrated in FIG. 35, an apparatus770 for installing a suture retainer 772 is disclosed. In the embodimentof the invention illustrated in FIG. 36, a second apparatus forinstalling a suture retainer is disclosed. Since the embodiment of theinvention illustrated in FIG. 36 is similar to the embodiment of theinvention illustrated in FIG. 35, similar terminology will be utilizedto identify similar components.

An apparatus or tool 870 for positioning a suture retainer 872 relativeto body tissue 54 includes a base or housing 874. A cylindrical plunger876 is slidable in the housing 874. The plunger 876 is connected withleft and right force application or clamp members 880 and 882 by a pairof linkages 884. Although only one of the linkages 884 has been shown inFIG. 36, it should be understood that there is a second linkage havingthe same construction as the linkage 884 connected with the plunger 876.

A biasing spring 888 extends around the plunger 876 and urges theplunger upward (as viewed in FIG. 36). The force transmitted from thebiasing spring 888 through the plunger 876 and linkages 884 urges theleft and right force application members 880 and 882 into engagementwith the suture retainer 872. The force provided by the spring 888 isinsufficient to cause significant deformation of the suture retainer872. However, the force provided by the spring 888 is sufficient toenable the force application members 880 and 882 to hold the sutureretainer 872 during sliding of the suture retainer along the suture 52.

A transducer or load cell 892 is connected with the plunger 876 andprovides an output signal, over a lead 894 to a display unit 896. Thisoutput is indicative of the magnitude of the force transmitted throughthe plunger 876. When a predetermined force has been applied by theforce application members 880 and 882 against the suture retainer 872for a predetermined minimum length of time, an indicator 898 isactivated by the display unit 896.

The specific suture retainer 872 illustrated in FIG. 36 has a one-piecetubular cylindrical construction. The suture 52 has left and rightsections 66 and 68 which are wrapped around the suture retainer 872 inthe same manner as in which the suture 52 is wrapped around the sutureretainer 50 of FIG. 2. Thus, a loop 904 is formed in the left section 66of the suture 52 and extends around a portion of the tubular cylindricalsuture retainer 872. Similarly, a loop 906 is formed in the rightsection 68 of the suture 52 and extends around a portion of the tubularcylindrical suture retainer 872.

In the embodiment of the invention illustrated in FIG. 36, a forcedistribution member or button 910 is provided at the upper side surface98 of the body tissue 54. The force transmission member or button 910distributes the force applied by the suture retainer 872 to the bodytissue 54 over a relatively large area on the body tissue. If desired, asecond force distribution member could be provided between the sutureand a lower side surface 108 of the body tissue 54. Since the sutureretainer 872 is effective to apply force to a relatively large area, thebutton 910 may be omitted if desired.

When the suture retainer 872 is to be installed in the body tissue, thetwo sections 66 and 68 of the suture are sewn through the body tissue 54and are then inserted into the suture retainer 872. During insertion ofthe left and right sections 66 and 68 of the suture 52 into the sutureretainer 872, the loops 904 and 906 are formed in the two sections 66and 68 of the suture.

The plunger 876 is then manually moved downward in the housing 874against the influence of the biasing spring 888 to move the forceapplication members 880 and 882 apart. When the force applicationmembers 880 and 882 have been positioned adjacent to opposite sides ofthe suture retainer 872, the downward force applied against the plunger876 is released. This results in the biasing spring 888 moving theplunger 876 upward to actuate the linkages 884 to press the forceapplication members 880 and 882 against opposite sides of the sutureretainer 874.

The left and right sections 66 and 68 of the suture 52 are thentensioned. The apparatus or tool 870 is then moved along the left andright sections 66 and 68 of the suture 52 toward the body tissue. Asthis occurs, the loops 904 and 906 are displaced downwardly along thetensioned sections 66 and 68 of the suture 52 toward the body tissue.During downward displacement of the loops 904 and 906 toward the bodytissue 54, the left and right sections 66 and 68 of the suture 52 slidealong surfaces on the suture retainer 872.

After the suture retainer 872 has been moved into engagement with thebutton or force distribution member 910, the leading end of the sutureretainer 872 is pressed against the button with a predetermined force.This force is transmitted through the plunger 876 and is measured by thetransducer 892. Once the suture retainer 872 has been pressed againstthe button or force distribution member 910 with a predetermined force,the plunger 876 is manually pulled upward relative to the housing 874.This results in the transmission of force through the linkage 884 to theforce applying members 880 and 882.

The force applying members 880 and 882 apply sufficient force to thesuture retainer 872 to effect plastic deformation of the sutureretainer. At this time, the suture retainer is at a temperature belowthe transition temperature of the biodegradable polymeric material ofthe suture retainer. Thus, the suture retainer is at a temperature whichis the same as the temperature of the body tissue 54. The plasticdeformation of the suture retainer 872 results in cold flowing of thematerial of the suture retainer and gripping of the left and rightsections 66 and 68 of the suture 52 in the manner previously explainedin conjunction with the embodiments of the invention illustrated inFIGS. 1-35.

It should be understood that the tool 870 may be used to install any ofthe suture retainers illustrated in FIGS. 1-33. Of course, the forceapplication or clamp members 880 and 882 would be configured so as togrip the outer side surface of the specific suture retainer with whichthe tool is to be used.

Embodiment of FIGS. 37 and 38

In the embodiment of the invention illustrated in FIGS. 37 and 38, thesuture is tensioned with a force which is a function of a selectedsuture size and strength. Since the embodiment of the inventionillustrated in FIGS. 37 and 38 is similar to the embodiments of theinvention illustrated in FIGS. 1-36, similar terminology will beutilized to identify similar components.

A chart 918 setting forth various available suture sizes is illustratedschematically in FIG. 37. The chart 918 also sets forth the strength ofeach of the available suture sizes. It is contemplated that the specificstrength of a particular suture size may vary depending upon thematerial from which the suture is constructed and the manufacturer ofthe suture. By consulting the chart 918, a surgeon can select a sutureof a size and strength suitable for a particular use. Thus, a relativelylarge suture having substantial strength may be selected when bodytissue is to be connected with a bone or when portions of a bone are tobe interconnected by the suture. On the other hand, the relatively smallsuture size having a relatively small strength may be selected whendelicate body tissue, such as stomach or intestinal tissue, is to beinterconnected with the suture.

Once a suture of a size and strength suitable for retaining specificbody tissue has been selected, the suture is connected with body tissueand a retainer is moved along the suture toward the body tissue. Forceis transmitted from the suture retainer and from the suture to the bodytissue. The magnitude of the force which is transmitted from the sutureretainer and the suture to the body tissue will be a function of theselected size and strength of the suture.

The suture retainer may have any one of the constructions illustrated inFIGS. 1 through 36. Alternatively, the suture retainer could have anyone of the constructions illustrated in U.S. Pat. No. 5,593,425. It iscontemplated that the suture could be connected with body tissue in anyone of the manners illustrated in U.S. Pat. Nos. 5,593,425; 5,584,862;5,549,631; 5,527,343; and/or 5,464,426.

In the embodiment of the invention illustrated in FIG. 38, a suture 922extends through body tissue 924. The body tissue 924 includes an innerlayer 926 of body tissue and an outer layer 928 of body tissue. A firstor inner end portion 932 of the suture 922 is connected with a sutureanchor 934.

The suture anchor 934 could have any desired construction. For example,the suture anchor 934 could have a construction similar to any one ofthe constructions disclosed in U.S. Pat. Nos. 5,584,862; 5,549,631;and/or 5,527,343. However, the illustrated embodiment of the sutureanchor 934 is a circular disk or button having a pair of centralopenings around which the end portion 932 of the suture 922 is tied.

The suture 922 extends straight through the inner layer 926 and outerlayer 928 of body tissue 924. An outer side surface 938 of the innerlayer of body tissue 926 is engaged by an inner side surface 940 of theouter layer 928 of body tissue. The side surfaces 938 and 940 of the twosegments or layers 926 and 928 of body tissue are disposed in flatapposition. Thus, the outer side surface 938 of the inner layer 926 isdisposed in flat abutting engagement with the inner side surface 940 ofthe outer layer 928 where the suture 922 extends through the inner andouter layers.

A suture retainer 944 cooperates with the suture anchor 934 to hold thesuture 922 against movement relative to the body tissue 924. The sutureretainer 944 has a spherical configuration. A cylindrical passage 946extends axially through the suture retainer 944.

Although the suture 922 (FIG. 38) extends straight through the passage946 in the suture retainer 944, bends and/or loops could be formed inthe suture 922 around the suture retainer 944 in the manner illustratedin FIG. 2. Thus, two bends, corresponding to the bends 72 and 74 of FIG.2, could be formed in the suture 922 by wrapping a turn of the suturearound a portion of the suture retainer 944. This will result in theformation of a single loop, corresponding to the loop 86 of FIG. 2,around the suture retainer 944.

The suture retainer 944 is formed of one piece of spherical polymericmaterial having a relatively low coefficient of friction. The sutureretainer 944 may be formed of many different materials. However, it isbelieved that it will be preferred to form the suture retainer 944 of abiodegradable polymer. One biodegradable polymer which may be utilizedis polycaperlactone. Alternatively, the suture retainer 944 could beformed of polyethylene oxide terephthalate or polybutyleneterephthalate. It is also contemplated that other biodegradable orbioerodible copolymers could be utilized if desired.

Although it is preferred to form the suture retainer 944 of abiodegradable material, the suture retainer could be formed of amaterial which is not biodegradable. For example, the suture retainercould be formed of acetyl resin, such as “Delrin” (trademark).Alternatively, the suture retainer 944 could be formed ofpara-dimethylamino-benzenediazo sodium sulfonate, such as “Dexon”(trademark).

The suture 922 may be formed of natural or synthetic materials. Thesuture 922 may be a monofilament or may be formed of a plurality ofinterconnected filaments. The suture 922 may be biodegradable ornon-biodegradable. It may be preferred to form the suture 922 of thesame material as the suture retainer 944. However, the suture 922 couldbe formed of a material which is different than the material of thesuture retainer.

In accordance with a feature of the embodiment of the inventionillustrated in FIGS. 37 and 38, the suture 922 is tensioned with a forcewhich is a function of the size and strength of the suture, as indicatedby the chart 918. In addition, the suture retainer 944 is pressedagainst the body tissue 924 with a force which is also a function of thesize and strength of the suture 922, as indicated by the chart 918 ofFIG. 37. Although the suture 944 is disposed in direct engagement withand is pressed against an outer side surface 950 of the outer layer orsegment 928 of body tissue 924, a force distribution member or buttoncould be positioned between the suture retainer 944 and the outer sidesurface 950 of the outer layer 928 of body tissue.

The suture 922 is tensioned by a force application assembly 954 which isconnected with the second or outer end portion 956 of the suture 922.The force application assembly 954 includes a transducer or load cell958 which provides an output signal indicative of a force, indicatedschematically at 960 in FIG. 38 which is applied to the second or outerend portion 956 of the suture 922. The force 960 has a magnitude whichis a function of the size and strength of the suture 922, as indicatedby the chart 918. Thus, the force 960 may be equal to 0.80 times thestrength of the suture 922 as indicated by the chart 918. Of course, thestrength of the suture 922 will vary with variations in the size of thesuture 922.

The suture retainer 944 is pressed against the outer side surface 960 ofthe outer layer or segment 928 of body tissue 924 with a force which isalso a function of the strength and size of the suture 922, as indicatedby the chart 918 of FIG. 37. A force application member 944 is used toapply force against the suture retainer 922. The force applicationmember 964 has a cylindrical opening 966 which extends through the forceapplication member. The suture 922 extends through the opening 966. Aslot may be formed in the force application member 964 to enable thesuture 922 to be moved into the opening 966. Alternatively, the suture922 could be inserted through the opening 966 before the end portion 956of the suture is connected with the force application assembly 954.

Forces, indicated schematically at 968 and 970 in FIG. 38, are appliedagainst opposite end portions 972 and 974 of the force applicationmember 964 to press the suture retainer 944 directly against the outerlayer 928 of body tissue or against a force transmitting member disposedbetween the suture retainer 944 and the outer layer 928 of body tissue.The combined force, indicated schematically the arrows 968 and 970 inFIG. 38, is a function of the size and strength of the suture 922, asindicated by the chart 918. It is contemplated that the combined forces968 and 970 may be equal to the force 960. In the specific examplepreviously mentioned, this would result in the forces 968 and 970 havinga sum or total equal to 0.80 times the strength of the suture 922 asindicated by the chart 918. Alternatively, the summation of the forces968 and 970 could exceed the force 960 or be less than the force 960.

The suture retainer 944 slides downward (as viewed in FIG. 38) along thesuture 922 under the influence of the force application member 964. Atthis time, the suture 922 is tensioned by the force application assembly954 so that the portion of the suture extending between the sutureanchor 934 and the force application assembly 954 is straight, asillustrated in FIG. 38. However, at this time, the force which isapplied to the outer end portion 956 of the suture 922 by the forcetransmitting assembly 954 may be substantially less than the force whichis indicated schematically by the arrow 960 in FIG. 38.

After the suture retainer 944 has been moved along the suture 922 to theposition illustrated in FIG. 38, the force applied against the sutureretainer by the force application member 964 is increased. At the sametime, the force applied to the outer end portion 956 of the suture 922by the force application assembly 954 is increased. The force appliedagainst the suture retainer 944 by the force application member 964 isincreased until the force, indicated schematically by the arrows 968 and970 in FIG. 38, is equal to a predetermined function of the strength ofthe suture 922, as indicated by the chart 918 for the particular size ofthe suture. At the same time, the force applied to the outer end portion956 of the suture 922 by the force application assembly 954 is increasedto the force indicated schematically by the arrow 960 in FIG. 38. As waspreviously mentioned, the force indicated by the arrow 960 is apredetermined function of the strength of the suture 922 as indicated bythe chart 918.

While the suture 922 is being pulled straight under the influence oftension in the suture due to the force 960 and while the suture retainer944 is being pressed against outer layer 928 of body tissue or against asuitable force distribution member, the suture retainer 944 isplastically deformed to firmly grip the suture 922. Thus, while thesuture retainer 944 is being pressed against the outer layer 928 of bodytissue 924 under the combined forces 968 and 970 and while the suture922 is being tensioned by the force 960, a pair of force applicationmembers 978 and 980 are pressed against opposite sides of the sutureretainer 944. The force applied against the suture retainer 944 by theforce application members 978 and 980 plastically deforms the materialof the suture retainer.

In the illustrated embodiment of the invention, the plastic deformationof the suture retainer 944 is effective to cause cold flowing of thematerial of the suture retainer. Force indicated by arrows 982 and 984in FIG. 38, is applied against the suture retainer 944 by the forceapplication members 978 and 980. This force is effective to causeflowing of the material of the suture retainer 944 at a temperaturebelow the transition temperature range of the material of the sutureretainer. Although the illustrated force application members 978 and 980have flat force transmitting surfaces, each of the force transmittingmembers could have force transmitting surfaces with a configurationcorresponding to the configuration of a portion of a sphere.

The cold flowing of the material of the suture retainer 944 results incollapsing of the passage 946 and in flowing of the material of thesuture retainer 944 around the portion of the suture 922 extendingthrough the passage 946. This enables the material of the sutureretainer 944 to bond to and obtain a firm grip on the suture 922. Thecold flowing of the material of the suture retainer 944 occurs at atemperature which is below the transition temperature of the materialforming the suture retainer.

It is believed that it may be preferred to plastically deform thematerial of the suture retainer 944 (FIG. 38) by applying force againstareas on the suture retainer and cold flowing material of the sutureretainer in the manner previously explained. However, if desired, thesuture retainer 944 may be heated before the force application members982 and 984 apply force against the suture retainer. The heated materialof the suture retainer will be moved into engagement with a portion ofthe suture 922 extending through the passage 946.

The temperature to which the material of the suture retainer is heatedwould be low enough so that the heated material would not causesignificant deformation of the material of the suture 922. Thus, thematerial of the suture retainer 944 may be heated to a temperaturewithin its transition temperature range but less than a temperaturewhich would result in a complete melting of the material of the sutureretainer. As the material of the suture retainer 944 is pressed againstthe suture 922 by the force application members 978 and 980, the heatedplastic material of the suture retainer is cooled to a temperature belowits transition temperature range. As this occurs, the plastic materialof the suture retainer 944 bonds to a portion of the suture 922 withoutsignificant deformation of the suture.

The interconnection between the material of the suture retainer 944 andthe portion of the suture 922 extending through the suture retainer isthe result of both molecular attraction (adhesion) of the material ofthe retainer to the material of the suture and due to a mechanicalinterconnection between the material of the suture retainer and thematerial of the suture. Thus, as the material of the suture retainer 944cools, it mechanically grips the suture 922 so that the suture is heldagainst movement relative to the suture retainer by interfacial forcesbetween the material of the suture retainer and the material of thesuture. There is a fusing of the material of the suture retainer 944 tothe material of the suture 922 along the portion of the suture whichextends through the suture retainer.

Whether the suture retainer 944 is plastically deformed by cold flowingthe material of the suture retainer or by a flowing of heated materialof the suture retainer, the suture retainer grips the suture 922 withoutsignificant deformation of the suture. Therefore, the strength of thesuture 922 is not impaired and corresponds to the strength indicated bythe chart 918 for the particular size of the suture.

When the layers or segments 926 and 928 of the body tissue 924 are to beinterconnected with the suture 922, the end portion 932 of the suture isconnected with an anchor member 934. The suture 922 is then threadedwith a needle or similar device, through the layers 926 and 928 of bodytissue.

It should be understood that in certain situations, a surgeon will nothave access to both the inner and outer sides of the body tissue. Insituations where the surgeon does not have access to both sides of thebody tissue, the anchor 934 is formed with a configuration which enablesit to be inserted through the layers or segments 926 and 928 of bodytissue along with the suture 922. Thus, the end portion 932 of thesuture 922 is connected with the anchor 934 while the anchor and sutureare both disposed outside of the patient's body.

The suture anchor, with the suture 922 connected thereto, is theninserted through both layers 926 and 928 of the body tissue 924. Thismay be accomplished in the manner disclosed in U.S. Pat. No. 5,464,426.However, it should be understood that the suture anchor could have aconfiguration other than the specific configuration disclosed in U.S.Pat. No. 5,464,426. For example, the suture anchor 934 could have aconfiguration similar to any one of the configurations disclosed in U.S.Pat. No. 5,527,343.

In the embodiment of the invention illustrated in FIG. 38, the sutureanchor 934 is positioned in engagement with an inner side surface 988 onthe inner layer 926 of body tissue. It is contemplated that the sutureanchor 934 could be disposed within the inner layer 926 of body tissue.Thus, the suture anchor could be disposed at a location midway betweenthe inner side surface 988 and the outer side surface 938 of the layer926 of body tissue. Mounting of the suture anchor in the body tissue inthis manner would be particularly advantageous if the suture anchor ismounted in bone in the manner illustrated in the aforementioned U.S.Pat. No. 5,527,343.

Although the suture retainer 944 has been illustrated in FIG. 38 ashaving a spherical construction, generally similar to the sutureretainer of FIGS. 1 and 2, it is contemplated that the suture retainer944 could have a configuration corresponding to the configuration of anyone of the suture retainers illustrated in FIGS. 1 through 36 herein.

Embodiment of FIG. 39

In the embodiment of the invention illustrated in FIGS. 37 and 38, thesuture 922 has a single section which extends through the sutureretainer 944. In the embodiment of the invention illustrated in FIG. 39,the suture has a plurality of sections which extend through the sutureretainer. Since the embodiment of the invention illustrated in FIG. 39is similar to the embodiment of the invention illustrated in FIGS. 1-38,similar terminology will be utilized to identify similar components. Itshould be understood that one or more features of the embodiment of theinvention illustrated in FIGS. 1-38 may be used with the embodiment ofthe invention illustrated in FIG. 39.

A suture retainer 1000 (FIG. 39) is utilized to secure a known suture1002 against movement relative to body tissue 1004. The suture 1002extends through an outer layer 1006 and an inner layer 1008 of the bodytissue. The suture 1002 has been illustrated schematically in FIG. 39 asextending through passages 1010 and 1012 in the outer and inner layers1006 and 1008 of body tissue 1004. However, the suture 1002 could besewn through the body tissue 1004 without forming the passages 1010 and1012 in the body tissue.

Although the suture 1002 has been shown in FIG. 39 in association withsoft body tissue, it is contemplated that the suture 1002 could beassociated with hard body tissue. It is also contemplated that thesuture 1002 could extend through a suture anchor in a manner similar tothat disclosed in U.S. Pat. Nos. 5,584,862; 5,549,631; and/or 5,527,343.

The suture 1002 has a left section 1016 and a right section 1018. Theleft and right sections 1016 and 1018 of the suture 1002 extend throughthe suture retainer 1000. If desired, the suture 1002 could beintegrally formed as one piece with the suture retainer 1000. If thiswas done, the end of the section 1016 or 1018 of the suture 1002 wouldbe connected with the suture retainer 1000. Alternatively, a singlesection of the suture 1002 could extend through the suture retainer, inthe manner illustrated for the embodiment of FIG. 38.

Although the sections 1016 and 1018 of the suture 52 could extendstraight through the suture retainer 1000, as shown in FIG. 38 for thesuture 922, it is preferred to form a plurality of bends in the suture1002. In the illustrated embodiment, bends are formed in the left andright sections 1016 and 1018 of the suture 1002 by wrapping a turn ofthe left section 1016 around a portion of the suture retainer 1000.Similarly, bends are formed in the right section 1018 of the suture 1002by wrapping a turn in the right section of the suture around a portionof the suture retainer 1000. A single loop is formed in the left section1016 of the suture 1002 around a portion of the suture retainer 1000.Similarly, a single loop is formed in the right section 1018 around aportion of the suture retainer 1000. A greater or lesser number of loopscould be provided in the left and right sections 1016 and 1018 ifdesired. The suture 1002 cooperates with the suture retainer 1000 in thesame manner as is illustrated in FIGS. 1 and 2 herein.

The suture retainer 1000 has a spherical configuration. A cylindricalpassage 1022 extends diametrically through the spherical suture retainer1000. If desired, the suture retainer 1000 could have a differentconfiguration. For example, the suture retainer 1000 could have any oneof the configurations illustrated in FIGS. 1 through 36. If desired, aplurality of passages having the same or different configurations, couldbe provided in the suture retainer 1000.

A surgeon selects the suture 1002 to have a particular size and strengthin accordance with a chart, corresponding to the chart 918 of FIG. 37. Aforce application assembly 1030 is connected with end portions of theleft and right sections 1016 and 1018 of the suture 1002. The forceapplication assembly 1030 tensions the suture 1002 with a force,indicated schematically by an arrow 1034 in FIG. 39.

In addition, a force application member 1038 applies force against thesuture retainer 1000 urging the suture retainer towards the body tissue1004. The force applied by the force application member 1038 to thesuture retainer 1000 moves or slides the suture retainer along thesuture 1002 toward the body tissue 1004. In the embodiment of theinvention illustrated in FIG. 39, the suture retainer 1000 is pressedagainst the outer layer 1006 of body tissue under the influence of forceapplied against the suture retainer 1000 by the force application member1038. However, if desired, a force distribution member, such as abutton, could be provided between the suture retainer 1000 and the bodytissue 1004. In addition, a force distribution member or button could beprovided between a connector section 1042 of the suture 1002 and theinner layer 1008 of body tissue.

In accordance with a feature of this embodiment of the invention, thesuture 1002 is tensioned by the force application assembly 1030, with aforce 1034 which is a function of the strength of the suture 1002. Inaccordance with another feature of this embodiment of the invention, theforce application member 1038 is effective to apply forces indicatedschematically by arrows 1046 and 1048, which are a function of thestrength of the suture 1002, to the suture retainer 1000.

The combined effects of the force application assembly 1030 and theforce application member 1038 result in the left and right sections 1016and 1018 of the suture 1002 being tensioned with a force which is afunction of the strength of the suture 1002 and in the transmission of aforce from the suture retainer 1000 to the body tissue 1004 which is afunction of the strength of the suture 1002. Thus, the force 1034 is afunction of the strength of the suture 1002. For example, the force1034, with which the suture 1002 is tensioned, may be equal to 0.80times the strength of the suture. Similarly, the combined forces 1046and 1048 which are transmitted from the suture retainer 1000 to the bodytissue 1004 may be 0.80 times the strength of the suture.

While the suture 1002 is being tensioned with the force 1034 and whilethe forces 1046 and 1048 are being applied to the suture retainer 1000to press the suture retainer against the body tissue, force applicationmembers 1052 and 1054 are effective to apply forces, indicatedschematically by arrows 1056 and 1058 against the suture retainer 1000.The force applied by the force application members 1052 and 1054plastically deforms the material of the suture retainer 1000.

The plastic deformation of the suture retainer 1000 is effective tocause cold flowing of material of the suture retainer. The forceindicated by the arrows 1056 and 1058 is applied against the sutureretainer 1000 by the force application members 1052 and 1054 for apredetermined length of time. This force is effective to cause flowingof the material of the suture retainer 1000 at a temperature below thetransition temperature range for the material of the suture retainer.Although the illustrated force application members 1052 and 1054 haveflat force transmitting surfaces, each of the force application members1052 and 1054 could have force transmitting surfaces with aconfiguration which corresponds to the configuration of a portion of asphere.

The cold flowing of the material of the suture retainer 1000 results ina collapsing of the passage 1022 and the flowing of the material of thesuture retainer around the sections 1016 and 1018 of the suture 1002.This enables the material of the suture retainer 1000 to bond to andobtain a firm grip on the suture 1002. The cold flowing of the materialof the suture retainer 1000 occurs at a temperature which is below thetransition temperature of the material forming the suture retainer.

During the time in which the force application members 1052 and 1058 areeffective to apply force against the suture retainer 1000, the sutureretainer is pressed against the outer layer 1006 of the body tissue 1004under the combined influence of the forces 1046 and 1048 which are afunction of the strength of the suture 1002. In addition, apredetermined tension is maintained in the sections 1016 and 1018 of thesuture 1002 by the force application assembly 1030. Thus, the sections1016 and 1018 of the suture 1002 tension with a force 1034 which is afunction of the strength of the suture 1002 while the force applicationmembers 1052 and 1054 are effective to plastically deform the materialof the suture retainer 1000.

Once the suture retainer 1000 has been plastically deformed to grip thesuture 1002, the force transmitting members 1052 and 1054 disengage fromthe suture retainer 1000. At the same time, the force application member1038 is moved away from the suture retainer 1000 and the forceapplication assembly 1030 interrupts the application of tensioning forceto suture 1002. The suture retainer 1000 grips the suture 1002 andmaintains the tension in the portions of the sections 1016 and 1018 ofthe suture which extend through the passages 1010 and 1012 even throughthe force application assembly 1030 is no longer effective to tensionthe suture.

The suture retainer 50 may be formed of many different materials.However, it is believed that it will be preferred to form the sutureretainer of a biodegradable polymer. Although it is preferred to formthe suture retainer 1000 of a biodegradable material, the sutureretainer could be formed of a material which is not biodegradable.

In the illustrated embodiment of the invention, the suture 1002 isformed of the same material as the suture retainer 1000. The suture 1002may be formed of a natural or synthetic material and may be amonofilament or formed by a plurality of interconnected filaments. Thesuture 1002 may be biodegradable or non-biodegradable.

In the foregoing description, the material of the suture retainer 1000has been plastically deformed by cold flowing of the material of thesuture retainer. It is contemplated that the suture retainer 1000 couldbe heated to a temperature in the transition temperature range for thematerial of the suture retainer. The force application members 1052 and1054 could apply force against the heated material of the sutureretainer 1000 to cause a flowing of the heated material of the sutureretainer.

Conclusion

The present invention provides a new and improved method and apparatusfor use in securing a suture 52 relative to body tissue 54. A sutureretainer 50 ((FIGS. 1-3) may be plastically deformed to grip the suture.The plastic deformation of the suture retainer 50 may include pressingthe material of the suture retainer against the suture 52 by coldflowing material of the suture retainer. The plastic deformation of thematerial of the suture retainer 50 may be performed while transmitting apredetermined force from the suture retainer 50 to the body tissue 54.

The strength of a connection between the suture retainer 50 and thesuture 52 may be increased by forming bends 72, 74, 76 and 78 in thesuture 52 before deforming the material of the suture retainer 50. Asthe suture retainer is moved along the first and second sections of thesuture toward the body tissue 54, the bends 72, 74, 76 and 78 are movedalong the suture with the suture retainer. The bends 72, 74, 76, and 78may be formed by wrapping the suture 52 around a circular portion of thesuture retainer (FIGS. 9, 13, 17, and 20), by moving the suture throughone or more passages in the suture retainer (FIGS. 2, 21, 23, 24, 25,26, and 29), by bending the suture around a member (FIG. 6), and/or bydeflecting a portion of the suture retainer through which the sutureextends (FIG. 32).

The suture retainer 50 may be gripped with a tool 770 or 870 which ismoved along the suture 52 to move the suture retainer toward the bodytissue 54. The tool 770 or 870 may be used to urge the suture retainertoward the body tissue with a predetermined minimum force. In addition,the tool 770 or 870 may be used to plastically deform the material ofthe suture retainer when the suture retainer has been moved to a desiredposition. The tool 770 or 870 may be used in association with any of theembodiments of the suture retainer illustrated in FIGS. 1-33.

It should be understood that the specific and presently preferredembodiments of the invention illustrated herein are only examples ofmany different embodiments of the invention which are possible. Indescribing the presently preferred embodiments of the inventionillustrated herein, similar terminology has been used to designatecomponents which are similar in structure and function. The specificfeatures of any one embodiment of the invention may be utilized inassociation with any of the other embodiments of the invention.

1. A non-implantable suture securing tool for scouring a suture againstbody tissue with a suture retainer, the tool comprising: a first forceapplication assembly removeably connectable with at least one endportion of the suture, the first force application assembly applyingtensioning force to the suture which is a function of suture size andstrength; a second force application assembly removeably engageable withthe suture retainer, the second force application assembly applying apressing force against the suture retainer in an extended positionthereby pressing the suture retainer against the body tissue, the secondforce application assembly having an opening through which the at leastone end portion of the suture is extendable and a biasing element urgingthe second force application assembly to the extended position; and athird force application assembly removable gripping the suture retainer,the third force application assembly applying a force to a side surfaceof the suture retainer, plastically deforming the suture retainer tothereby secure the suture against body tissue.
 2. The non-implantablesuture securing tool of claim 1 wherein the pressing force is a functionof suture size and strength.
 3. The non-implantable suture securing toolof claim 1 wherein the first force application assembly include atransducer for providing an output signal indicative of the tensioningforce.
 4. The non-implantable suture securing tool of claim 1 whereinthe third force application assembly includes a pair of forceapplication members.
 5. The non-implantable suture securing tool ofclaim 4 wherein each of the pair of force application members has a flatsurface for engaging the side surface of the suture retainer.
 6. Thenon-implantable suture securing tool of claim 4 wherein each of the pairof force application members includes a heating element for heating thesuture retainer.
 7. The non-implantable suture securing tool of claim 4wherein each of the pair of force application members has an arcuatesurface for engaging the side surface of the suture retainer.
 8. Thenon-implantable suture securing tool of claim 4 wherein each of the pairof force application members includes a plurality of bends configured toform a corresponding plurality of bends in the suture retainer uponapplication of the plastically deforming force to the side surface ofthe suture retainer.
 9. A non-implantable suture securing tool forsecuring a suture against body tissue with a suture retainer, the toolcomprising: a first force application assembly removable connectablewith at least one end portion of the suture for tensioning the suturewith a suture tensioning force which is a function of suture size andstrength; a second force application assembly for applying a pressingforce against a top surface of the suture retainer pressing the sutureretainer against the body tissue wherein the pressing force is afunction of suture size and strength, the second force applicationassembly having an opening through which the at least one end portion ofthe suture is extendable; and a third force application assembly whichremoveably grips and applies a force to a side surface of the sutureretainer, plastically deforming the suture retainer to thereby securethe suture against body tissue, the third force application assemblyhaving a biasing element applying a gripping force to the sutureretainer.
 10. The non-implantable suture securing tool of claim 9,wherein the first force application assembly includes a transducer forproviding an output signal indicative of the suture tensioning force.11. The non-implantable suture securing tool of claim 9 wherein thethird force application assembly includes a pair of force applicationmembers.
 12. The non-implantable suture securing tool of claim 11wherein each of the pair of force application members has a flat surfacefor engaging the side surface of the suture retainer.
 13. Thenon-implantable suture securing tool of claim 11 wherein each of thepair of force application members includes a heating element for heatingthe suture retainer.
 14. The non-implantable suture securing tool ofclaim 11 wherein each of the pair of force application members has anarcuate surface for engaging the side surface of the Suture retainer.15. The non-implantable suture securing tool of claim 11 wherein each ofthe pair of force application members includes a plurality of bendsconfigured to form a corresponding plurality of bends in the sutureretainer upon application of the plastically deforming force to the sidesurface of the suture retainer.